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MINERALOGY AND MINING. 


MINE ACCIDENTS—VENTILATION—ORE DRESSING, ETC. 


DESCRIPTIVE MINERALOGY. 
DANA. Comprising the most recent Discoveries. Fifth edition.  Al- 
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. APPENDICES TO DESCRIPTIVE MINERALOGY, 
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BRUSH, Completing the work to 1882. BY Prof. Geo. J. Brush and 


DANA. E. 8. Dana. ..8vo, limp cloth, 2 00 
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Fourth edition. Revised throughout and enlarged. Illustrated 
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PREFACE. 


Tue preface to the third edition of this work (1878) is as follows: 

‘‘This Manual in its present shape is new throughout. In the 
renovation it has undergone, new illustrations have been introduced, 
an improved arrangement of the species has been adopted, the table 
for the determination of minerals has been reconstructed, and the 
chapter on Rocks has been expanded to a length and fulness that 
renders it a prominent part of the work. But while modified greatly 
in all its parts, it is still simple in its methods of presenting the facts 
in crystallography, and in all other explanations; and special] prom- 
inence is given, as in former editions, to the more common minerals, 
with only a brief mention of others. The old practical feature is 
retained of placing the ores under the prominent metal they contain, 
and of giving in connection some information as to mines and mining 
indusiry. 

*« The student is referred to the Text-book of Mineralogy, prepared 
mainly by Mr. E. 8. Dana, for a detailed exposition of the subject of 
crystallography after Naumann’s and Miller’s systems, and also of 
optical mineralogy and other physical branches of the science; to the 
Manual of Determinative Mineralogy and Blowpipe Analysis by 
Professor GrEorGE J. Brusu, for a thorough work on the use of the 
biowpipe, and complete tables for the determination of minerals; and 
to the author’s Descriptive Mineralogy and its Appendixes for a com- 
prehensive treatise on minerals.” 

In this, the fourth, edition the general plan and scope of the work 
remain unchanged. But it has been revised throughout, and brought 
down to the year 1886 in its descriptions of minerals, and in the in- 
troduction of the many new species announced during the past eight 
years. The chapter on Rocks has been rewritten, rearranged, much 
enlarged, and supplied with new illustrations, The work is greatly 
indebted, for facts about ores and other useful minerals, to the exccl- 
lent annual report on the ‘‘ Mineral Resources of the United States,” 
by Mr. Albert Williams, Jr., published by the United States Geologi- 
eal Survey. The author would acknowledge also his obligations to 
Prof. B. J. Harrington, of Montreal, for the revision of the list of 
localities in Ontario and Quebec. 


JAMES D. Dana. 
New Haven, Dec. 15, 1886. 


my) 4 : 
795182 





TABLE OF CONTENTS. 


MINERALOGY. 
PAGE 
PemmnaAus. General Remarks)... so. ec cscs ecco cbeseccee 1 
I. CRYSTALLIZATION OF MINERALS: CRYSTALLOG- 
RAPHY. 

1. General Remarks on Crystallization. ..........0.ceceeeees 4 
Beeceerpions Of Orystals:.ceecisie ce cde sadecccevectessede 8 
MURERTISICNY Cie PETING tie ese ohne naka occa es een o's ostche' 6 8 
Measurement of Angles; Goniometers................. 9 

1. SysTEMS OF CRYSTALLIZATION : Forms and Struc- 
ture of Crystals...... eitee corte s oritatci a are aden 
RM SPIS VSCOM, 555 dicl. a aoe ae Ss ge's cise os 6 ojnripmids one bin Kas 18 
RTM CIVICS aldo aie, © dec sis) eis’ a oie 0 si0. eins. cins ssei60 <0 a0 ae 31 
BPPPEICROMUIG SV BUCTING « « tie'p «og uuSiia sie 'e'ae'ie ogee ence seve 38 
SE INOS VIET a) Capielo-e sale « 0 siervinns: ciao: 22s. o.sie Salp.wieeiaw 4s. 41 
SE EN SAUTE al yon o'a top, wk tie 0 6.45.6 «<0 0, 010e 4.008 adios b's 45 
SIRES PURITY lee sca o's. p main edn nc s-ten ee siele. ae 6 sion ¢ sie00 47 
PURE AO ONAL DCCUOM we ore'e dic one. c.c,08.0)s:mecciieiers ern weiseae 47 
Pnompouedra lk: Becton cn. «5 soe dia okielcaelely walle Uelelile 51 
%, Distinguishing Characters of the Systems................. 56 
2. TWIN oR CoMPOUND ORYSTAIS.......... sete rete 57 
oo) PARAMORPHS ;- PARAMORPHISM..0.....00c0cs oe ce 61 
4, PSEUDOMORPHS ; PSEUDOMORPHISM.........ee00. 61 
5. ORYSTALLINE AGGREGATES...........205 sevteae st GG 


II. PHYSICAL PROPERTIES OF MINERALS. 


NITES rote toe tect cet te sedate c coca scl e cc cus 67 
I CLES ccc cress cas nie te cscs sceat access: wee cp 67 


Vil TABLE OF CONTENTS. 
: : PAGE 
3. Specific Gravity ..........sc00e veeete ce eso oop tee AOS 
4, Refraction and Polarization :....0.. 0d ..s< see uenene 70 
5.. Diaphancity, Lustre, Color. . is. i033 .s 05.52. 0eewe es eee 80 
6. Electricity, and-Magnetism......<ss.00 ces es cemtee saeene 84 
To Taste; Odor, 2... S20 da vec cees fee ona ee ee oe Seat a 
Ill. CHEMICAL PROPERTIES OF MINERALS. 
4. Chemical Composition ..:..0% ¢... ssi «02's ss oy eee 86 
2... ChemicalsResctions... 55 ..< .50s-ec0< 00s seers ccels ieee 92 
A. \Trials'in the Wet Way. «....%... ..<« ¢ssueeie aan 92 
B. Trials with the Blowpipe.. .'s..+. .:<sss.s 9 seeneenen 93 
_IV. DESCRIPTIONS OF MINERALS. 
TZ, Classification... ....s:.\s:00 "aisles bese bx 2 aid cee svat 103 
2. General Remarks on Ores..........000. ‘Seles a ss 5 104 
I, MINERALS CONSISTING OF THE ACIDIC HLEMENTS. 
1; Sulphur Group. ....« .'s.2 vs v0re i's o's ow 6:0 40s hee oh kay 106 
A. SOTO Group. ... 02 cecctc ccess ced epiasicisinsithy | cn 109 
3. Arsenic’ Group :.i...52 0800s 00s beac s ove seg Stent 110 
4. Carbon Group........... TEP ISTE ERE Ey ei 115 


Il. MINERALS CONSISTING OF THE Basic ELEMENTS 
WITH OR WITHOUT ACIDIC—THE SILICATES EX- 


CLUDED. . 
CTOs wted cscs ¢ shure henekes aeenutee o cele a’ u's dle'sesl de mietatnne 
Silver.and.its Compounds, ......00'5\s s0.0\0ssisc.cie ote e amen 129 
Platinum, Iridium,. Ruthenium... 3. ss036 5.0.) Seen sles OU 
Palladium........ ; oss 9.9 o.9-0.0)0 nayntanis 0 pele y se ce rn 141 
Mercury, and.its Compounds... 3.0. «00+ ce s<W ab satan sa phs seers 142 
Copper and its Compounds............ je chs 3 Ree 145 
Lead and its: Compounds... sis .' 5.0% 5 0a.e e's «6 ge elo e oer 160 
Zinc and its Compounds,» .°2 5's <i00c «a0 oeebee © oes 5 mene 170 
Cadmitim, Tin. ... 2.05. 40's seis 'e-wtelu’atetolsieteeejate aisle alae Mit ann 175 
Compounds of Titanium. «oon: sv as «sovwn's tee oe ee eee 178 
Cobalt and Nickel and their Compounds,.................... 180 
Uranium andits Compounds. ..... .:0:.% sss sees suhe sk see 186 
Tron‘and tts Compounds...) <2» sawed dws (so ts aay enn 188 


Manganese and its Compounds....:....s s0+ses0'ees ene een 206 


TABLE OF CONTENTS. Vii 


: PAGE 
momnouneds Of Aluminium... .3...%6...660sewries thas vaste oe 211 

Compounds of Cerium, Yttrium, Erbium, Lanthanum, and 
RRGIMSUIY D2 tere vines cle ehS obiee dao see ald deve ces ole sialh gee 221 
PeerE ONL MBONICSIUIN 2. 3 sis eivecaik 6s debe te eres ovine ss 223 
MEE MM CTE ASRICTUINE S275 '2 et 44 5 oso ee ala gas ele a's eee ave's 227 
Compounds of Barium and Strontium............... Sst cae: 240 
Compounds of Potassium and Sodium ............eeeeeeeee 243 
Compounds of Ammonium... .:.iiccs.ccccccccdedcccdscwencs 249 
Compounds of Hydrogen........... (tie 4 vk de ge hes Aide EP iE 

III, Sinica AND SILICATES, 
1. SILICA. 
BUROATEM nis eos scsascveccee RE RO EO ee ciliates eagle <claese),208 
TE oats eras esc 6 ccc occ osu siegheese ees REA Ree 
2. SILICATES. 
MIETETTIAL RS oe ory aoe ccc cen k hee vec sse ees ideuseeveuden: OOo 
1. Anhydrous Silicates. 

eee LCN YT ty): ot sae Soe 5 2 oon oe shee 6 titers covonee eres 263 
Pyroxene and Amphibole Group...........seeeeeee- 265 
POE e PRCT a viet ass sleet See salsa ethralse e's cere o witch e 274 
Pep brisilicated p86 ye. iG cee oe ys oe ots OE or 275 
SENSO GLO sy iia has awe ae s'ne 6 eeae sunteid s O6d0'e «.« 277 
REAPBOUCITOUL go go s'a Kacey css s'¥ees AEST eR i ena 278 
SeIOTE AS LOUP Pie irdle: 6 atvlvcventela cs veh! MS hatatte vie emotes 281 
eEPIAULE,. UDCOURs CLG ia a's vivscinied se cc cteus s oxides 282 
PASOATES LG septa ade tale 'g oar aoe aber aig! atl eee SR Ao Oe 0 286 
Dantusrito,, LON. 6. x CEA Gos oS e selene ea 286 
PEPER Tien onl w Cendds ocak cca dien kiwis aie» ote oe roe s 287 
PAGANO. GOUT: « cx -0e nce nclale sk vcioeis ¢ ot oar ae © caee 292 
Nephelite, Sodalite, Leucite....... aes how cteta toes 293 
MPEDCEDAP ARTOUTL, 2 vist’, « aacinitbince oa clots sb we mek eweNls 296 
COO or ee a rar TE ECE er ae Me ete 302 
OG GT COTS FT pga ae a me One Sm RGR a gg MR t ara gl 303 
PE MFCLEITILLINIG.. oc Pa iain iile, ops aed winnie b,c ooo eRe awe 304 
Andalusite, Fibrolite, Cyanite. ..........ccesceecess 306 
PP ORAZ, SEAICI ESO dain: v'vhe 074 ses p's tole awe wea a's Le a 309 
PIALOLUDS SIDDENE a1. -ceeie s'e'a'e deh etic cman wae date Piae ba 311 


SETA TITOMLG schadainre'ary'sie'e'c'e'ate oo ee et die a wae ee eed rete 813 


Vili TABLE OF CONTENTS, 


2. Hydrous Silicates. 


PAGE 
1. General Seationje. ids. .:ssesiSuidtie - auncceaten os > eich a eens 
Pectolite, Laumontite, Apophyllite...... +a dentvcaei eae 815 

Prehnite, Allophane... «...-\sstsigese's cus «9:0 sle.aiatee anne 

B Zeolite Sections, «is «is cies b's ce Cacies ee < Weare + sind ke 
Thomsonite;. NatrOlite:: sisi. sistslois pein Dine » lorie ele 320 

Analcite, Chabazite, 2 ¢ 3% div sseew comics, Siete see 822 
Harmotome, Stilbite.....--.csuuewese o » Cisjeie aie eee 
Heulandite, ... oss. oases s 00 secakeeiet: Gener ves Bao 

3. Margarophyllite Section. ..........ccceeees o's sis Se 326 
Talc, Pyrophyllite, Sepiolite ... +... «sss oe sue eee 326 
Glauconite 222 Pres oe Seas one oe ete ose 829 
Serpentine, Deweylite, Saponite ....... co gc! eae 329 

Kaolinite, Pinite....... en fod ica 332 
Hydromics Groupist:c2. ova o ssc saan AP foe y- 335 
Fidhibanites Scere cca sta cle vents Seats ey ale apie 33. 336 . 

Chiorite Group. viimamraimbens ay'r's ea sacs wee ° oslo a veit nae 

IV. HypDROocARBON COMPOUNDS. 
1.28imple Hydrocarbons. ;< . 225.2% a sless as clds'etleiouew ails seceees B42 
2, Oxygenated Hydrocarbons. ¢. .% snags Ao s eee a teimeaal Peer ls 
$,2Asphaltum, Mineral Coals. ..35 ..'sescss++ +> swam iene ee Pee: 349 
SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
Catalogue of American Localities of Minerals............... vee. O08 
V. DETERMINATION OF MINERALS. 
Ganeral HGMiarks,. «sk. «ocis «ss «ocala wn ateion aeete o wign'o oa 
Synopsis of the Arrangement...........sseeesvne cep sace octet 410 
Table for the Determination of Minerals...... «5:5 m0,.0:9:5/ein ela Se 
ON ROCKS. 

aConstituents Of Rocks.os sce soe nccaee Se's b'edwals ga bipianiate eid 
2. Distinctions among Hocks,...«:20sas eskee ease ssi ps cee 


3. The Investigation of Rocks........2esseceees a RRs eee 447 


TABLE OF CONTENTS. 1x 


PAGE 

4, Microscopic Characteristics of Rock Constituents......... wo» 454 
PE ECO ROCKS <. voy oes geek Oh ee eer tee cee eeeN 457 
I, Calcareous Rocks or Limestones ...........esesceceees 457 

II. Fragmental Rocks, exclusive of Limestones........... 461 

III. Crystalline Rocks, exclusive of Limestones............ 466 

A. Siliceous Rocks, consisting mainly of Silica...... 468 


B. Containing Feldspar, Mica, Leucite, Nephelite, 
Sodalite, or other related Alkali-bearing 


RECESS eee see esas os ce i ek ee tiene es 469 
a. Potash-Feldspar and Mica Series............. 469 

b. Potash-Feldspar and Hornblende or Pyroxene 
Berea. Lass Sev vaeire need eer ee one pe 47 

c. Potash-Feldspar and Nephelite Series, Horn- 
bieniic Gr notre. as hae erences 478 
d. Leucite Rocks, with or without Augite....... 479 
e. Soda-Lime-Feldspar and Mica Series......... 480 

jf. Soda-Lime-Feldspar and Hornblende or Pyrox- 
GNGLIMOCKS a e-via ands anals clei s det eres aise at bre 480 
SORE EMOUSHUTIEO? HOCKB rufa. advise uc asics deesse 0 eeene SOE 
PPR PeOCKS WILIOUE CHISUEl ec cwecs soselses s'xele ss es 487 


1. Garnet, Epidote, and Tourmaline Rocks..... 487 
2. Hornblende, Pyroxene, and Chrysolite Rocks. 488 


E. Hydrous Magnesian and Aluminous Rocks....... 489 
Pee rauiity, in HOCKS,......0.+ cece eRe ea ree tis'e.s eee ES 491 
ACADEMY COLLECTION OF MINERALS.............. se cece ceeees 495 


RRR To a ccs eiics Cates ceceverwveoses soeecne aoe 





MINERALOGY. 


MINERALS. 


MINERALS are the materials of which the earth consists, 
and plants and animals the living beings over the surface 
of the mineral-made globe. <A few rocks, like limestone 
and quartzite, consist of a single mineral in more or less 
pure state; but the most of them are mixtures of two or 
more minerals. Through rocks of each kind various other 
minerals are often distributed, either in a scattered way, or 
in veins and cavities. Gems are the minerals of jewelry; 
and ores, those that are important for the metal they con- 
tain. Water is a mineral, but generally in an impure state 
from the presence of other minerals in solution, The at- 
mosphere, and all gaseous materials set free in volcanic and 
other regions, are mineral in nature, although, because of 
their invisibility, seldom to be found among the specimens 
of mineral cabinets. Even fossils are mineral in composi- 
tion. ‘This is true of coal which has come from buried 
plant-beds, and amber from the buried resin of ancient 
trees, as well as of fossil shells and corals. 

It is sometimes said that minerals belong to the mineral 
kingdom, as plants to the vegetable kingdom, and animals 
to the animal kingdom. Substituting the term tnorganic 
for mineral, the statement is right; for, as there are the 
two kingdoms of life, so there is in Nature what may be 
called a kingdom, or grand division, including all species 
not made through the organizing principle of life. But 
this Inorganic kingdom is not restricted to minerals; it 
embraces all species made by inorganic forces; those of the 
earth’s crust or surface, and, also, whatever may form un- 
der the manipulations of the chemist. The laws of com- 
position and structure, exemplified in the constitution of 
rocks, are those also of the laboratory. A species made by 

1 


2 CHARACTERS OF MINERALS. 


art, as we term it, is not a product of art, but a result 
solely of the fundamental laws of composition which are at 
the basis of all material existence; and the chemist only 
supplies the favorable conditions for the action of those 
laws. Mineral species are, then, but a very small part of 
those which make up the inorganic kingdom or division of 
Nature. 


CHARACTERS OF MINERALS. 


1. Minerals, unlike most rocks, have a definite chemical 
composition. This composition, as determined by chemi- 
cal analysis, serves to define and distinguish the species, 
and indicates their profoundest relations. Owing to differ- 
ence in composition, minerals exhibit great differences 
when heated, and when subjected to various chemical rea- 
gents, and these peculiarities are a means of determining . 
the kind of mineral under examination in any case. The 
department of the science treating of the composition of 
minerals and their chemical reactions is termed CHEMICAL 
MINERALOGY. 

2. Each mineral, with few exceptions, has its definite 
form, by which, when in good specimens, it may be known, 
and as truly so as a dog or cat. These forms are cubes, 
prisms, double pyramids, and the like. They are included 
under plane surfaces arranged in symmetrical order, ac- 
cording to mathematical law. These forms, in the mineral. 
kingdom, are called crystals. Besides forms, there is also, 
as in living individuals, a distinctive internal structure for 
each species. The facts of this branch of the science come 
under the head of CRYSTALLOGRAPHIC MINERALOGY. 

3. Minerals differ in hardness—from the diamond at one 
end of the scale to soapstone at the other. ‘There is a still 
lower limit in liquids and gases; but of the hardness or co- 
hesion in this part of the series the mineralogist has little 
occasion to take note. | 

Minerals differ in specific gravity, and this character, 
like hardness, is a most important means of distinguishing 
species. 

Minerals differ in color, transparency, lustre, and other 
optical characters. 

A few minerals have faste and odor, and when so these 
characters are noticed in descriptions. 


CHARACTERS OF MINERALS. 3 


The facts and principles relating to the above characters 
are embraced in the department of PHysicAL MINER- 
ALOGY. 

In addition to the above-mentioned branches of the sci- 
ence of minerals there is also (4) that of D&rscRIPTIVE 
MINERALOGY, under which are included descriptions of 
the mineral species; and (5) that of DETERMINATIVE MIN- 
ERALOGY, which gives a systematic review of the methods 
for determining or distinguishing minerals. 

These different branches of the subject are here taken up 
in the following order: I. Crystallographic Mineralogy; 
II. Physical Mineralogy; III. Chemical Mineralogy; IV. 
Descriptive Mineralogy; V. Determinative Mineralogy. 
On account of the brief manner in which the subjects are 
treated in this volume, the heads used for the several parts 
are, (1) The Crystallization of Minerals; (2) Physical 
Properties of Minerals ; (3) Chemical Properties of Miner- 
als; (4) Descriptions of Species; (5) Determination of 
Minerals. 


4 CRYSTALLOGRAPHY, 


I, CRYSTALLIZATION OF MINERALS: CRYSTAL- 
LOGRAPHY. 


1. GENERAL REMARKS ON CRYSTALLIZATION. 


THE attraction which produces crystals is one of the 
fundamental properties of matter. It is identical with the 
cohesion of ordinary solidification; for there are few cases 
outside of the kingdoms of life in which solidification takes 
place without some degree of crystallization. Cohesive at- 
traction is, in fact, the organizing or structure-making 
principle in inorganic nature, it producing specific forms 
for each species of matter, as life does for each living spe- 
cies. A bar of cast-iron is rough and hackly in surface, 
because of the angular crystalline grains which the iron 
assumed as solidification took place. A fragment of mar- 


= AN 


, Z 


ES : 
eo a 
‘ 1 INS 


2 





CRYSTALS OF SNOW. 


ble glistens in the sun, owing to the reflection of light 
from innumerable crystalline surfaces, every grain in the 
mass having its crystalline structure. When the cold of 
winter settles over the earth in the higher temperate and 
colder latitudes it is the signal for crystallization over all 
out-door nature; the air is filled with crystal flakes when 
it snows; the streams become coated with an aggregation 


CRYSTALLOGRAPHY. 5 


of crystals called ice; and windows are covered with frost 
because crystal has been added to crystal in long feathered 
lines over the glass—Jack Frost’s work being the making 
of crystals. Water cannot solidify without crystallizing, 
and neither can iron nor lead, nor any mineral material, 
with perhaps half a dozen exceptions. Crystallization pro- 
duces masses made of crystalline grains when it cannot 
make distinct crystals. Granite mountains are mountains 
of crystals, each particle being crystalline in nature and 
structure. ‘The lava current, as it cools, becomes a mass 
of crystalline grains. In fact the earth may be said to 
have crystal foundations; and if there is not the beauty of 
external form, there is everywhere the interior, profounder 
beauty of universal law—the same law of symmetry which, 
when external circumstances permit, leads to the perfect 
crystal with regular facets and angles. 

Crystals are alone in making known the fact that this 
law of symmetry is one of the laws of cohesive attraction, 
and that under it this attraction not only brings the par- 
ticles of matter into forms of mathematical symmetry, but 
often develops scores of brilliant facets over their surface 





een AS fs mi 


with mathematical exactness of angle, and the simplest of 
numerical relations in their positions. Crystals teach also 
the more wonderful fact that the same species of matter 


6 CRYSTALLOGRAPHY. 


may receive, under the action of this attraction, through 
some yet incomprehensible changes in its condition, a great 
diversity of forms—from the solid of half a dozen planes 
to one of scores. The above figures represent a few of the 
forms in a common species, pyrite, a compound of iron 
and sulphur. 


8. Feu 10. 





Many more figures might be given for this one species, 
pyrite. The various forms or planes in any such case have, 
it is true, mutually dependent relations—a fact often ex- 


CRYSTALLOGRAPHY. v4 


pressed by saying that they have a common fundamental 
form. But it is none the less a remarkable fact, giving pro- 
found interest to the subject, that the attraction, while 
having this degree of unity in any species, still, under each, 
admits of the multitudinous variations needed to produce 

so diverse results. ; 

At the time of crystallization the material is usually in a 
state of fusion, or of gas or vapor, or of solution. In the 
case of iron the crystallization takes place from a state of 
fusion, and while the result is ordinarily only a mass of 
crystalline grains, distinct crystals are sometimes formed in 
any cavities. If in the cooling of a crucible of melted lead, 
bismuth, or sulphur the crust be broken soon after it forms, 
and the liquid part within be turned out, crystals will 
be found covering the interior. Here, also, is crystalliza- 
tion from a state of fusion. When frost or snow-flakes 
form it exemplifies crystallization from a state of vapor. 
If a saturated solution of alum, made with hot water, be 
left to cool, crystals of alum after a while will appear, 
and will become of large size if there is enough of-the 
solution. A solution of common salt, or of sugar, affords 
crystals in the same way. Again, whenever a mineral is 
produced through the change or decomposition of another, 
and at the same time assumes the solid state, it takes at 
once a crystalline structure, if it does not also develop crys- 
tals. 

Further, the crystalline texture of a solid mass may often 
be changed without fusion: e.g., in tempering steel the 
bar is changed from coarse-grained steel to fine-grained by 
heating and then cooling it suddenly in cold water, and 
vice versa, and this is a change in every grain throughout 
the bar. 

Thus the various processes of solidification are processes 
of crystallization, and the most universal of all facts about 
minerals is that they are crystalline in texture. A few ex- 
ceptions have been alluded to, and one example of these is 
the mineral opal, in which even the microscope detects no 
evidence of a crystalline condition, except sometimes in 
minute portions supposed not to be opal. But if we ex- 
clude coals and resins this mineral stands almost alone. 
Such facts, therefore, do not affect the conclusion that a 
knowledge of crystallography is of the highest importance 
to the mineralogist. It is important because— 


8 CRYSTALLOGRAPHY. 


1, A study of the crystalline forms and structure of 
minerals is a convenient means of distinguishing species— 
the crystals of a species being essentially constant in struc- 
ture and in angles. 

2. The most. important optical characters depend on the 
crystallization, and have to be learned from crystals. 

3. ‘The profoundest chemical relations of minerals are 
often exhibited in the relations of their crystalline forms. 

4, Crystallization opens to us Nature at her foundation 
work, and illustrates its mathematical character. 


2. DESCRIPTIONS OF CRYSTALS. 


In describing crystals there are two subjects for con- 
sideration: First, Form; and secondly, STRUCTURE. 

A. Foru.—Under form come up for description, not 
only the general forms of crystals, but also— 

(1) The systems of crystallization, that is, the relations 
of all crystalline forms, and their classification. 

(2) The mutual relations of the planes of a crystal as 
ascertained through their positions and the angles between 
them. 

(3) The distortions of crystals. The perfection of sym- 
metry exhibited in the figures of crystals, in which all 
similar planes are represented as having the same size and 
form, is seldom found in nature, and the true form is often 
greatly disguised by this means. ‘The facts on this point, 
and the methods of avoiding wrong conclusions, need to be 
understood, and these are given beyond. With all such 
imperfections the angles of crystals remain essentially con- 
stant. There are irregularities also from other sources. 

(4) Twin or compound crystals. With some species 
twins are more common than regular crystals. 

(5) Crystalline aggregates, or combinations of imperfect 
crystals, or of crystalline grains. 


Explanations of Terms. 


The following are explanations of a few terms used in connection 
with this subject: 

1. Octahedron.—A solid bounded by eight equal triangles. They 
are equal equilateral triangles in the regular octahedron (Fig. 2, p. 18) ; 
equal isosceles triangles in the sguare octahedron (Fig. 17, p. 38); 
equal inequilateral triangles in the rhombic octahedron (Fig. 8, p. 38). 


CRYSTALLOGRAPHY. 9 


2. Double six-sided pyramids. Double eight-sided pyramids. Double 
twelve-sided pyramids.—Solids made of two equilateral six-sided, or 
eight-sided, or twelve-sided, pyramids placed base to base (Fig. 20, p. 
33, and 6, 10, pp. 48, 49). 

3. Right prisms. Oblique prisms.—Right prisms are those that are 
erect, all their sides being at right angles to the base. When inclined, 
they are called oblique prisms. 

4, Interfacial angle.—Angle of inclination between two faces or 

lanes. 
: 5. Similar planes. Similar angles.—The lateral faces of a square 
prism (Fig. 2, p. 15) are equal and have like relations to the axes, and 
hence they are said to be similar. Solid angles are s¢midlar when the 
plane angles are equal each for each, and the enclosing planes are sev- 
erally similar in their relations to the axes. 

6. Truncated.  Bevelled.i—An edge of a crystal is said to be trun- 
cated when it is replaced by a plane equally inclined to the enclosing 
planes, asin Fig. 13, p. 20; and it is bevelled when replaced by two 
planes equally inclined severally to the adjoining faces. Only edges 
that are formed by the meeting of two s¢émilar planes can be truncated 
or bevelled. The angle between the truncating plane and the plane 
adjoining it on either side always equals 90° plus half the interfacial 
angle over the truncated edge. When a rectangular edge, or one of 
90°, is truncated, this angle is accordingly 185° (= 90° + 45°); when 
an edge of 70°, it is 125° (= 90° + 85°); when an edge of 140”, it is 
160° (= 90° + 70°). 

7%. Zone.—A zone of planes includes a series of planes having the 
edges between them, that is, their mutual intersections, all parallel. 
Thus in Fig. 14, on page 6, H at top of figure, 72, 73, H in front, and 
two planes below, and others on the back of the crystal are in one zone, 
a vertical zone. Again, in the same figure, # at top, 42, 38, 22, 42, 72, 
42, 22, 38, and the continuation of this series below and over the back 
of the crystal lie in another vertical zone. And so in cases in 
other directions. All planes in the same zone may be viewed as on the 
circumference of the same circle. The planes of crystals are generally 
all comprised in a few zones, and the study of the mathematics of 
crystals is largely the study of zones of planes. 

Axes.—Imaginary lines in crystals intersecting one another at their 
centres. Axes are assumed in order to describe the positions of the 
planes of crystals. ~In each system of crystallization there is one verti- 
cal axis, and in all but hexagonal forms there are two lateral axes. 

Diametral sections.—The sections of crystals in which lie any two of 
the axes. In forms having two lateral axes, there are two vertical 
diametral sections and one basal. 

Dianetral prisms.—Prisms whose sides are parallel to the diametral 
sections. 


Measurement of Angles. 


The angles of crystals are measured by means of instruments called 
gontometers. These instruments are of two kinds, one the common 
goniometer, the other, the reflecting goniometer. 


10 CRYSTALLOGRAPHY. 


The common goniometer depends for its use on the very simple prin- 

ciple that when two straight lines cross one an- 

A a other, as AH, CD, in the annexed figure, the parts 

will diverge equally on opposite sides of the point 

0 of intersection (Q); that is, in mathematical lan- 

c E guage, the angle AOD is equal to the angle OOH, 
and AOC is equal to DOL. 

: A common form of the instrument is represented in the figure be- 

Ow. 

The two arms ad, cd, move on a pivot at 0, and their divergence, 
or the angle they make with one another, is read off on the graduated 
arc attached. In using it, press up between the edges ao and co 
the edge of the crystal whose angle is to be measured, and con- 
tinue thus opening the arms until these edges lie evenly against the 
faces that include the required angle. To insure accuracy in this 
respect, hold the instrument and crystal between the eye and the light, 
and observe that no light passes between the arm and the applied faces 
of the crystal. The arms may then be secured in position by tighten- 
ing the screw at 0; the angle will then be measured by the distance on 
the arc from * to the left or outer edge of the arm ed, this edge being 
in the line of 0, the centre of motion. As the instrument stands in the 
figure, it reads 45°. The arms have slits at gh, np, by which the 
parts ao, co, may be shortened so as to make them more convenient 
for measuring small crystals. 

In the best form of the common goniometer the arc is a complete 





circle, of larger diameter than in the above figure, and the arms are 
separate from it. After making the measurement, the arms are laid 

upon the circle, with the pivot at the centre of motion inserted ina 
socket at the centre of the circle. The inner edge of one of the arms 

4 then brought to zero on the circle, and the angie is read off as be- 
ore. 


CRYSTALLOGRAPHY. 11 


With a little ingenuity the student may construct a goniometer for 
himself that will answer a good purpose. A semicircle may be de- 
scribed on mica or a glazed card, and graduated. The arms might 
also be made of stiff card for temporary use; but mica, bone, or metal 
is better. The arms should have the edges straight and accurately 
parallel, and be pivoted together. The instrument may be used like 
that last described, and will give approximate results, sufficiently near 
for distinguishing most minerals. ‘The ivoryrule accompanying boxes 
of mathematical instruments, having upon it a scale of sines for measur- 
ing angles, will answer an excellent purpose, and is as convenient as 
the arc. 

In making such measurements it is important to have in mind the 
fact that— 

1. The sum of the angles about a centre is 360°. 

Ses In a rhomb, as in a square, the sum of the plane angles is 
as 

In any polygon, the supplements of the angles equal 360°, whatever 
the number of sides. For example: in a square, the four angles are 
each 90°, and hence the supplements are 90°, and 4x80=360; again, 
in a regular hexagon the six angles are each 120, the supplements are 
60°, and 6<60=360. So for all polygons, whether regular or irregular, 
In measuring the angles it is therefore convenient to take down the 
supplements of the angles. This principle is conveniently applied in 
the measurement of all the angles of a zone of planes around the 
crystal; for the sum of all the supplements should be, as above, 360°, 
and if this result is not obtained there is error somewhere. 

The reflecting goniometer affords a more accurate method of 
measuring crystals that have lustre, and may be used with those of 
minute size. The principle on which this instrument is constructed 
will be understood from the annexed figure, representing a crystal, 
whose angle adc is required. The eye, look- 
ing at the face of the crystal bc, observes a 
reflected image of m, in the direction Pn. On 
revolving the crystal till a has the position of 
bc, the same image will be seen again in the 
same direction Pr. As the crystal is turned, 
in this revolution, till abd has the present 
position of dc, the angle ddc measures the 
number of degrees through which it is revolved. But dbe subtracted 
from 180° equals the angle of the crystal abe. The crystal is there- 
fore passed, in its revolution, through a number of degrees equal to 
the supplement of the required angle. 

This angle, in the reflecting goniometer of Wollaston, one form of 
which is represented in the following figure, is measured by attaching 
the crystal to a graduated circle which revolves with it. 

C is the graduated circle. The wheel, m, is attached to the main 
axis, and moves the graduated circle together with the adjusted crys- 
tal. The wheel, n, is connected with an axis which passes through 
the main axis (which is hollow for the purpose), and moves merely the 
parts to which the crystal is attached, in order to assist in its adjust- 
ment. The contrivances for the adjustment of the crystal are at a, d, 
c,d, k. 'The screws, c, d, are for the adjustment of the crystal, and 
the slides, a, 6, serve to centre it. 





12 CRYSTALLOGRAPHY. 


To use the instrument, it may be put on a stand or small table, with 
its base accurately horizontal, and the table placed in front of a win- 
dow, six to twelve feet off, with the plane of its circle at right angles 
to the window. A line must then be drawn below the window, near 
or on the floor, parallel to the bars of the window, and about as far 
from the eye as from the window-bar. 

The crystal is attached to the movable plate * by means of wax, and 
so arranged that the edge of intersection of the two planes forming the 

























































































required angle shall be in a line with the axis of the instrument. 
This is done by varying its situation on the plate, or by means of the 
adjacent screws and slides. 

When apparently adjusted, the eye must be brought close to the 
crystai, nearly in contact with it, and on looking into a face, part of 
the window will be seen refiected, one bar of which must be selected 
for the trial. If the crystal is correctly adjusted, the selected bar 
will appear horizontal, and on turning the whecl », till this bar, as 
reflected, is observed to approach the dark line below seen in a direct 
view, it will be found to be parallel to this dark line, and ultimately to 
coincide with it. The eye for both observations should be held in 


CRYSTALLOGRAPHY. 13 


precisely the same position. If there is not a perfect coincidence, the 
adjustment must be altered until this coincidence is obtained. Con- 
tinue then the revolution of the wheel n, till the same bar is seen by 
reflection in the next face, and if here there is also a coincidence of 
the reflected bar with the dark line seen direct, the adjustment is com- 

lete; if not, alterations must be made, and the first face again tried. 

n an instrument like the one figured, the circle is usually graduated 
to twenty or thirty minutes, and, by means of the vernier, minutes and 
half minutes are measured. After adjustment, 180° on the arc must 
be brought opposite 0, on the vernier, v. The coincidence of the bar 
and dark line is then to be obtained, by turning the wheel ». When 
obtained, the wheel m should be turned until the same coincidence is 
observed, by means of the next face of the crystal. Ifa line on the 
graduated circle now corresponds with 0 on the vernier, the angle is 
immediately determined by the number of Gegrees opposite this line. 
If no line corresponds with 0, we must observe which line on the 
vernier coincides with one on the circle. If it is the 18th on the 
vernier, and the line on the circle next below 0 on the vernier marks 
125°, the required angle is 125° 18’; if this latter line marks 125° 20’, 
the required angle is 125° 38’. 

In the better instruments other improved methods of arrangement 
are employed; and in the best, often called Mitscherlich’s goniometer, 
because first devised by him, there are two telescopes, one for passing 
a ray of light upon the adjusted crystal, having crossed hair-lines in its 
focus, and the other for viewing it, also with a hair-cross. With such 
an arrangement, the window-bar and dark line are unnecessary, the 
hair-crosses serving to fix the position of the crystal, and the telescope 
that of the eye. If the crystal is perfect in its planes, and the adjust- 
ment exact, the measurement, with the best instruments, will give the 
angle within 10”. 

Other goniometers have only the second of the two telescopes just 
alluded to, as is the case inthe figure on page 12. This telescope gives 
a fixed position to the eye; and through it is seen a reflection of some 
distant object, which may be even a chimney-top. For the measure- 
ment the object, seen reflected in the two planes successively, is 
brought each time into conjunction with the haircross. Exact ad- 
justment is absolutely essential, and with an instrument having the two 
telescopes, the first step in a measurement cannot be taken without it. 

Only small, well-polished crystals can be accurately measured by the 
reflecting goniometer. If, when using the instrument without tele- 
scopes, the faces do not reflect distinctly a bar of the window, the 
flame of a candle or of a gas-burner, placed at some distance from the 
crystal, may be used by observing the flash from it with the faces in 
succession as the circle is revolved. A ray of sunlight from a mirror, 
received on the crystal through a small hole, may be employed in a 
similar way. But the results of such measurements will be only 
approximations. With two telescopes and artificial light, and with a 
cross-slit to let the light pass in place of the cross-hairs of the first of 
the above mentioned telescopes, this light-cross will be reflected from 
the face of a crystal even when it is not perfect in polish, and quite 
good results may be obtained. 


14 CRYSTALLOGRAPHY. 


B. StTRUCTURE.—Structure includes cleavage, a charac- 
teristic of crystals intimately connected with their forms 
and nature. It is the property, which many crystals have, 
of admitting of subdivision indefinitely in certain directions, 
and affording usually even, and frequently polished, sur- 
faces. The direction is always parallel with the planes of 
the axes, or with others diagonal to these. 

The ease with which cleavage can be obtained varies 
greatly in different minerals, and in different directions in 
the same mineral. In a few species, like mica, it readily 
yields laminz thinner than paper, and in this case the 
cleavage is said to be eminent. Others, of perfect cleavage, 
cleave easily, but afford thicker plates, and from this stage 
there are all grades to that in which cleavage is barely dis- 
cernible or difficult. 'The cleavage surfaces vary in lustre 
from the most brilliant to those that are nearly dull. When 
cleavage in a mineral is alike in two or more directions, — 
that is, is attainable in these directions with equal facility 
and affords surfaces of like lustre and character or mark- 
ing, this is proof that the planes in those directions are 
‘similar, or have similar relations to like axes. Jor ex- 
ample, equal cleavage in three directions, at right angles to 
one another, shows that the planes of cleavage correspond 
to the faces of the cube; so equal cleavage in ¢wo directions, 
in a prismatic mineral, shows that the planes in the two 
directions are those of a square prism, or else of a rhombic 
prism; and if they are at right angles to one another, that 
they are those of the former. This subject is further illus- 
trated beyond. 


In the following pages (1) the Systems of Crystallization 
and the Forms and Structure of Crystals are first con- 
sidered; next, (2) Compound or Twin Crystals; (3) Para- 
morphs; (4) Pseudomorphs; and (5) Crystalline Aggre- 
gates. 


SYSTEMS OF CRYSTALLIZATION, 15 


1, SYSTEMS OF CRYSTALLIZATION: FORMS 
AND STRUCTURE OF CRYSTALS. 


The forms of crystals are exceedingly various, while the 
systems of crystallization, based on their mathematical dis- 
tinctions, are only six in number. Some of the simplest of 
the forms under these six systems are the prisms represented 
in the following figures; and by a study of these forms the 


1. 
= SA 





distinctions of the six systems will become apparent. These 
prisms are all four-sided, excepting the last, which is six- 
sided. In them the planes of the top and bottom, and any 
planes that might be made parallel to these, are called the 
basal planes, and the sides the /ateral planes. An imaginary 
line joining the centres of the bases (c in Figs. 1 to 8) is 
called the vertical axis, and the diagonals a and 0, drawn 
in a plane parallel to the base, are the lateral azes. 

Fig. 1 represents a cube. It has all its planes square 
(like Fig. 9), and all its plane and solid angles, right angles, 
and the three axes consequently cross at right angles (or, in 
other words, make rectangular intersections) and are equal. 
Tt is an example under the first of the systems of crystalli- 
zation, which system, in allusion to the equality of the axes, 
is called the Jsometric system, from the Greek for equal 
and measure. 

Fig. 2 represents an erect or right square prism having 


« 


16 CRYSTALLOGRAPHY. 


all its plane angles and solid angles rectangular. ‘The base 
is square or a tetragon, and consequently the lateral axes 
are equal and rectangular in their intersections; but, unlike 
a cube, the vertical axis is unequal to the lateral. There 
are hence, in the square prism, axes of two kinds making 
rectangular intersections. ‘The system is hence called, in 
allusion to the tetragonal base, the Tetragonal system. 

Fig. 3 represents an erect or right rectangular prism, in 
which, also, the plane angles and solid angles are rectangu- 


Ji 


lar. The base is a rectangle (Fig. 10), and consequently the 
lateral axes, connecting the centres of the opposite lateral 
faces, are wnequal and rectangular in their intersections ; 
and, at the same time, each is wnequal to the vertical. 
There are hence three unlike axes making rectangular in- 
tersections ; and the system is called, in allusion to the 
three unlike axes and in allusion also to its including erect 
prisms having a rhombic base, the Orthorhombic system, 
orthos, in Greek, signifying straight or erect. 

This rhombic prism is represented in Fig. 4. It has a 
rhombic base, like Fig. 11; the lateral axes connect the 
centres of the opposite lateral edges ; and hence they cross 
at right angles and are unequal, as in the rectangular prism. 
This right rhombic prism is therefore one in system with 
the right rectangular prism. 

Fig. 5 represents another rectangular prism, and Fig. 6 
another rhombic prism ; but, unlike Figs. 3 and 4, the prisms 
are inclined backward, and are therefore odligue prisms. . 
The lateral axes (a, 0) are at right angles to one another and 
unequal, as in the preceding system; but the vertical axis 
is inclined to the plane of the lateral axes. It is inclined, 
however, to only one of the lateral axes, it being at right 
angles to the other. Hence, of the three angles of axial 
intersection, two are rectangular, namely, a on d, and ¢ ond, 
while one is oblique, that is, ¢ (the vertical axis) on a. In 
allusion to this fact, there being only one oblique angle, 


SYSTEMS OF CRYSTALLIZATION. LY 


this system is called the Monoclinic system, from the Greek 
for one and inclined. 

Fig. 7 represents. an oblique prism with a rhomboidal 
base (like Fig. 12). The three axes are unequal and the 
three axial intersections are all oblique. ‘The system is 
called the 7'riclinic system, from the Greek for ¢hree and 
inclined. 

Fig. 8 represents a six-sided prism, with the sides equal 
and the base a regular hexagon. The lateral axes are here 
three in number. ‘T'hey intersect at angles of 60°; and 
this is so, whether these lateral axes be lines joining the 
centres of opposite lateral planes, or of opposite lateral 
edges, as a trial will show. ‘The vertical axis is at right 
angles to the plane of the three lateral axes, inasmuch as 
the prism is erect or right. The base of the prism being a 
regular hexagon, the system is called the Hexagonal system. 

The systems of crystallization are therefore : 

I. The Isometric system : the three axes rectangular in 
intersections ; equal. 

II. The TETRAGONAL system: the three axes rectangular 
in intersections ; the two lateral axes equal, and unequal to 
the vertical. 

III. The OrTHORHOMBIC system : the three axes rectan- 
gular in intersections, and unequal. 

IV. The Monociinic system: only one oblique inclina- 
tion out of the three made by the intersecting axes; the 
three axes unequal. 

V. The TRIcLINIC system: all the three axes obliquely 
inclined to one another, and unequal. 

VI. The HEXAGONAL system: the vertical axis at right 
angles to the lateral; the lateral three in number, and in- 
tersecting at angles of 60°. 

These six systems of crystallization are based on mathe- 
matical distinctions, and the recognition of them is of great 
value in the study and description of crystals. Yet these 
distinctions are often of feeble importance, since they some- 
times separate species and crystalline forms that are very 
close in their relations. There are forms under each of 
the systems that differ but little in angles from some of 
other systems: for example, square prisms that vary but 
slightly from the cubic form ; triclinic that are almost iden- 
tical with monoclinic forms; hexagonal that are nearly cu- 
bic. Consequently it is found that the same natural group 

2 


18 CRYSTALLOGRAPHY. 


of minerals may include both orthorhombic and mono- 
clinic species, as is true of the Hornblende group ; or mono- 
clinic and triclinic, as is the fact with the Feldspar group, 
and soon. It is hence a point to be remembered, when 
the affinities of species are under consideration, that differ- 
ence in crystallographic system is far from certain evidence 
that any species are fundamentally or widely unlike. 


I. THE ISOMETRIC SYSTEM. 


1. Descriptions of Forms—The following are figures of 
some of the forms of crystals under the isometric system: 








The first is the cube or hexahedron, already described. 
Besides the three cubic axes, there are equal diagonals in 
two other directions; one set connecting the apices of the 
diagonally opposite solid angles, fows i number (because 
the number of such angles is eight), and called the octahe- 
dral axes ; and another set connecting the centres of the 
diagonally opposite edges, six in number (because the num- 
ber of edges is twelve), and called the dodecahedral azes. 

Fig. 2 represents the octahedron, a solid contained under 
eight equal triangular faces (whence the name from the 
Greek eight and face), and having the three axes like those 
in thecube. Its plane angles are 60°; its interfacial angles, 
that is, the inclination of planes 1 and 1 over an intervening 


ISOMETRIC SYSTEM. 19 


edge (usually written 1 A 1) = 109° 28’ (more exactly 109° 
28’ 16"); and 1 on 1 overa solid angle, 70° 32’. 

Fig. 3 is the dodecahedron, a solid contained under twelve 
equal rhombic faces (whence the name from the Greek for 
twelve and face). . The position of the cubic axes is shown 
in the figure. It has fourteen solid angles; six formed by 
the meeting of four planes, and eight formed by the meet- 
ing of three. The interfacial angles (or 7 on an adjoining 
1) are 120°; 7 on 7 over a four-faced solid angle = 90°. 

Fig. 4 is a trapezohedron, a solid contained under 24 equal 
trapezoidal faces. There are several different trapezohe- 
drons among isometric crystalline forms. The one here 
figured, which is the common one, has the angle over the 
edge B, 131° 49’, and that over the edge C, 146° 27”. A 
trapezohedron is also called a tetragonal trisoctahedron, the 
faces being tetragonal or four-sided, and the number of 
faces being 3 times 8 (¢ris, octo, in Greek). 

Fig. 5 is another trisoctahedron, one having trigonal 
or three-sided faces, and hence called a trigonal trisoctahe- 
dron. Comparing it with the octahedron, Fig. 2, it will be 
seen that three of its planes correspond to one of the octa- 
hedron. The same is true also of the trapezohedron. 

Fig. 6 is a tetrahexahedron, that is, a 4x 6-faced solid, 
the faces being 24 in number, and four corresponding to 
each face of the cube or hexahedron (Fig. 1). 

Fig. 7 is a hexoctahedron, that is, a 6x 8-faced solid, a 
pyramid of six planes corresponding to each face in the 
octahedron, as is apparent on comparison. ‘There are dif- 
ferent kinds of hexoctahedrons known among crystallized 
isometric species, as well as of the two preceding forms. 
In each case the difference is not in number or general ar- 
rangement of planes, but in the angles between the planes, 
as explained beyond. 

But these simple forms very commonly occur in combina- 
tion with one another; a cube with the planes of an octahe- 
dron and the reverse, or with the planes of any or all of the 
other kinds above figured, and many others besides. More- 
over, all stages between the different forms are often repre- 
sented among the crystals of a species. ‘Thus between the 
cube and octahedron occur the forms shown in Figs. 8 to 
11. Fig. 12 is acube; Fig. 8 represents the cube with a 
plane on each angle, equally inclined to each cubic face; 9, 
the same, with the planes on the angles more enlarged and 


20 CRYSTALLOGRAPHY. 


the cubic faces reduced in size; and then 10, the octahe- 
dron, with the cubic faces quite small; and Fig. 11, the 
octahedron, the cubic faces having disappeared altogether. 
This transformation is easily performed by the student with 
cubes cut out of chalk, clay, or a potato. It shows the fact 





that the cubic axes (Fig. 12) connect the apices of the solid 
angles in the octahedron. 

Again, between a cube and a dodecahedron there occur 
forms like Figs. 18 and 14; Fig. 12 being a cube, Fig. 13 the 
same, with planes truncating the edges, each plane being 
equally inclined to the adjacent cubic faces, and Fig. 14 an- 
other, with these planes on the edges large and the cubic 
faces small; and then, when the cubic faces disappear by 
further enlargement of the planes on the edges, the form is 
a dodecahedron, Fig. 15. The student should prove this 
transformation by trial with chalk or some other material, 
and so for other cases mentioned beyond. ‘The surface of 
such models in chalk may be made hard by a coat of muci- 
lage or varnish. 

Again, between a cube and a trapezohedron there are the 
forms 17 and 18; 16 being the cube; 16, cube with three 
planes placed symmetrically on each angle; 18, the same 
with the cubic faces greatly reduced (but also with small 
octahedral faces), and 19, the trapezohedron, the cubic 
faces having disappeared. 

Again, Fig. 20 represents a cube with three planes on each 


ISOMETRIC SYSTEM. 21 


angle, which, if enlarged to the obliteration of the faces of 
the cube, become the trigonal trisoctahedron, Fig. 21. So 





again, Fig. 22 represents a cube with six faces on each angle, 
which, if enlarged to the same extent as in the last, would 
become the hexoctahedron, Fig. 23. 
_ Again, Fig. 25 isa form between the octahedron (Fig. 24) 





and dodecahedron (Fig. 26); and Figs. 27 and 28 are forms 
between the dodecahedron, Fig. 26, and trapezohedron, 
Fig. 29. 


22. CRYSTALLOGRAPHY. 
Again, Fig. 30 is a form between a cube (Fig. 16) and a 


tetrahexahedron, Fig. 31; Fig. 32, a form between an octa- 
hedron, Fig. 24, and a tetrahexahedron, Fig. 31; Fig. 33, a 


a. 
Cb & 


form between an octahedron and a trigonal trisoctahedron, 
Fig. 34; Fig. 35, a form between a dodecahedron (planes 7) 








and a tetrahexahedron; Fig. 36, a form between the dodeca- 
hedron and a hexoctahedron, Fig. 37. 

Fig. 38 represents a cube with planes of both the octa- 
hedron and dodecahedron. 


2, Positions of planes with reference to the axes, Lettering 


of figures.—The numbers by which the planes in the above figures, 
and others of the work, are lettered, indicate the positions of the planes 
with reference to the axes, and exhibit the mathematical symmetry and 
ratios in crystallization. In the figure of the cube (Fig. 1) the three axes 
are represented; the lateral semi-axis which meets the front planes in the 
figure is lettered a; that meeting the side plane to the right 4, and the 
vertical axis c, and the other halves of the same axes respectively -a, 
-b, -c. By a study of the positions of the plancs of the cube and other 
forms with reference to these axes, the following facts will become 
apparent, 


ISOMETRIC SYSTEM. ya 


In the cube (Fig. 1) the front plane touches the extremity of axis a, 
but is parallel to axes band c. When one line or plane is parallel to 
another they do not meet except at an infinite distance, and hence the 
sien for infinity is used to express parallelism. Employing ?, the initial 
of infinity, as this sign, and writing c¢, 6, a, for the semi-axes so lettered, 
then the position of this plane of the cube is indicated by the expres- 
sion 7c: 7b: 1a. The top and side-planes of the cube meet one axis and 
are parallel to the other two, and the same expression answers for each, 
if only the letters a, d, c, be changed to correspond with their positions. 
The opposite planes have the same expressions, except that the c¢, 0, a, 
will refer to the opposite halves of the axes and be -c, -d, -a. 

In the dodecahedron, Fig. 15, the right of the two vertical front 
planes 7 meets two axes, the axes a and 4, at their extremities, and is 
parallel to the axis c. Hence the position of this plane is expressed by 
t#¢:1b:1a. So, all the planes meet two axes similarly and are parallel 
to the third. The expression answers as well for the planes @ in Figs. 
13, 14, as for that of the dodecahedron, for the planes have all the 
same relation to the axes. 

In the octahedron, Fig. 11, the face 1 situated to the right above, 
like all the rest, meets the axes a, 0, c, at their extremities; so that the 
expression 1c : 1 : 1a answers for all. 

Again, in Fig. 17 (p. 21) there are three planes, 2-2, placed symmet- 
rically on each angle of a cube, and, as has been illustrated, these are 
the planes of the trapezohedron, Fig. 19. The upper one of the planes 
2-2 in these figures, when extended to meet the axes (as in Fig. 19), 
intersects the vertical ¢ at its extremity, and the others, a and 2, at 
twice their lengths from the centre. Hence the expression for the 

lane is 1c: 2b: 2a. So, as will be found, the left-hand plane 2-2 on 

ig. 17, will have the expression 2¢ : 10: 2a; and the right-hand one, 
2c:2b:1a. Further, the same ratio, by a change of the letters for the 
semi-axes, will answer for all the planes of the trapezohedron. 

In Fig. 20 there are other three planes, 2, on each of the angles of a 
cube, and these are the planes of the trisoctahedron in Fig. 21. The 
lower one of the three on the upper front solid angle, would meet if 
extended, the extremities of the axes a and }, while it would meet the 
vertical axis at twice its length from the centre. The expression 2c: 
1d : 1a indicates, therefore, the position of the plane. So also, 1c: 10: 
2a and 1c: 2: la represent the positions of ‘he other two planes ad- 
joining; and corresponding expressions may be similarly obtained for 
all the planes of the trisoctahedron. 

Again, in Fig. 30, of the cube with two planes on each edge, and in 
Fig. 31, of the tetrahexahedron bounded by these same planes, the left 
of the two planes on the front vertical edge of Fig. 80 (or the corre- 
sponding plane on Fig. 31) is parallel to the vertical axis; its intersections 
with the lateral axes, ~and 3, are at unequal distances from the centre, 
expressed by the ratio 2b: 1a. This ratio for the plane adjoining on 
the right is 10: 2a. ‘The position of the former is expressed by the 
ratio 7c : 2b : 1a, and for the other by 7c: 10: 2a. Thus, for each of the 
planes of this tetrahexahedron the ratio between two axesis 1 : 2, while 
the plane is parallel to the third axis. 

Again, in Fig. 22, of the cube with six planes on each solid angle, 
and in the hexoctahedron in Fig. 23, made up of such planes, each of 
the planes when extended so that it wili meet one axis at once its 


24 CRYSTALLOGRAPHY. 


length from the centre, will meet the other axes at distances expressed 
by a constant ratio, and the expression for the lower right one of the 
six planes will be 3c: 35: 1a. By a little study, the expressions for the 
other five adjoining planes can be obtained, and so also those for all 
the 48 planes of the solid. 

In the isometric system the axes, a, b, c, are equal, so that in the 
general expressions for the planes these letters may be omitted; the 
expressions for the above-mentioned forms thus become— 


Cube (Fig. 1), ¢: 1: ¢. Tetrahexahedron (Fig. 5), 7:1: 2. 
Octahedron (Fig. 2), 1:1: 1. Trigonal trisoctahedron (Fig. 6), 
Dodecahedron (Fig. 3), 1:1: 7. a, Sake 
Trapezohedron (Fig. 4), 2:1:2. Hexoctahedron (Fig. 7), 3:1: 3. 


Looking again at Fig. 17, representing the cube with planes of the 
trapezohedron, 2: 1: 2, it will be perceived that there might be a tra- 
pezohedron having theratios 14:1:14, 38:1:38, 4:1:4, 5:1:5, 
and others; and, in fact, such trapezohedrons occur among crystals. 
So also, besides the trigonal trisoctahedron 2: 1:1 (Fig. 21), there 
might be, and there in fact is, another corresponding to the expression 
8: 1:1; and still others are possible. And besides the hexoctahedron 
3:1: 3 (Fig. 28), there are others having the ratios 4:1:2, 4:1: 4, 
5: 1:4, and so on. 

In the above ratios, the number for one of the lateral axes is always 
made a unit, since only a ratio is expressed; omitting this in the ex- 
pression, the above general ratios become: for the cube, 7: 7; for the 
octahedron, 1:1; dodecahedron, 1:7; trapezohedron, 2:2; tetra- 
hexahedron, ¢@: 2; trigonal-trisoctahedron, 2:1; and hexoctahedron, 
3:2. In the lettering of the figures these ratios are put on the planes, 
but with the second figure, or that referring to the vertical axis, first. 
Thus the lettering on the hexoctahedron (Fig. 23), is3-3; on the trigonal 
trisoctahedron (Fig. 21) is 2, the figure 1 being unnecessary; on the 
tetrahexahedron (Fig. 31), 7-2; on the trapezohedron (Figs. 4 and 19), 
2-2; on the dodecahedron (Fig. 15), 7; on the octahedron, 1; on the 
cube, 7-2, in place of which H is used, the initial of hexahedron. In 
the printed page these symbols are written with a hyphen in order to 
avoid occasional ambiguity, thus 3-8, 7-2, 2-2, etc. Similarly, the 
ratios for all planes, whatever they are, may be written. The numbers 
are usually small, and never decimal fractions. 

The angle between the planes 7-2 (or 7: 1: 2) and H, in Fig. 30, page 
22, may be easily calculated, and the same for any plane of the series 
i-n(¢:1:%n). Draw the right-angled triangle, ADC, 
as in the annexed figure, making the vertical side, 
CD, twice that of AC, the base; that is, give them 
the same ratio as in the axial ratio for the plane. If 
A?=1, CD=2. Then, by trigonometry, making 
AC the radius, 1: R::2: tan DAC; or1: R::2: cot 
ADC. Whence tan DAC=cot ADC=2. By add- 
ing to 90°, the angle of the triangle obtained by 
working the equation, we have the inclination of the 
basal plane H, on the plane 7-2. So in all cases, 
whatever the value of 7 that value equals the tangent of 
the basal angle of the triangle (or the cotangent of the 
angle at the vertex), and from this the inclination to the cubic faces is 





A: C 


ISOMETRIC SYSTEM, 25 


directly obtained by adding 90°. If2—1, then the ratio is 1:1, as 
in ACB, and each angle equals 45°, giving 135° for the inclination on 
either adjoining cubic face. 

Again if the angles of inclination have been obtained by measure- 
ment, the value of 7 in any case may be found by reversing the above 
calculation; subtracting 90° from the angle, then the tangent of this 
angle, or the cotangent of its supplement, will equal 7, the tangents 
varying directly with the value of 7. 

In the case of planes of the m:1: 1 series (including 1:1:1, 2: 
1:1, etc.), the tangents of the angle between a cubic face in the same 
zone and these planes, less 90°, varies with the value of m. In the 
case of the plane 1 (or 1: 1: 1), the angle between it and the cubic face 
is 125° 16’. Substracting 90°, we have 35° 16’. Draw a right-angled 
triangle, OBC, with 35° 16’ as its vertex angle. BC has 
the value of 1c, or the semi-axis of the cube, Make 
DC=2BC, Then, while the angle OBC has the value 
of the inclination on the cubic face less 90° for the plane 
1:1:1, ODC has the same for the plane 2:1:1. Now, 
making OC the radius, and taking it as unity, BO is the 
tangent of BOC, or cot OBC, So DC = 2BC is the tan- B 
gent of DOC, or cot ODC. By lengthening the side CD 
(= 2BC or 2c) it may be made equal to 3BC = 3¢, its 
value in the case of the plane 3:1:1; or to4BC = 4e, 
its value in the case of the plane 4:1:1; or mBC=me 
for any plane in the series m:1:1; and since in all 0 C 
there will be the same relation between the vertical and 
the tangent of the angle at the base (or the cotangent of the angle at 
the vertex), it follows that the tangent varies with the value of m. 
Hence, knowing the value of the angle in the case of the form 1 
(1:1: 1), the others are easily calculated from it. 


BC being a unit, the actual value of OC is 4 V2, °F 74, it being 
half the diagonal of a square, the sides of which are 1, and from this 
value the angle 35° 16’ might be obtained for the angle OBO, 

- The above law (that, fora plane of the m: 1: 1 series, the tangent of 
its inclination on a cubic face lying in the same zone, less 90°, varies 
with the value of m, and that it may be calculated for any plane 
m:1:1 from this inclination in the form 1:1: 1), holds also for 
planes in the series m: 2:1, orm:3;1, or anym:n:1. That is, 
given the inclination of 0 on 1: 7: 1, its tangent doubled will be that 
of 2: 2:1, or trebled, that of 3: 7:1, and so on; or halved, it will be 
that of the plane 4+: 2: 1, which expression is essentially the same as 
1: 2n: 2. 

These examples show some of the simpler methods of applying ma- 
thematics in calculations under the isometric system. The values of 
the axes are not required in them, because a = b=c=1. 


3. Hemihedral Crystals—The forms of crystals described 
above are called holohedral forms, from the Greek for all 
and face, the number of planes being all that full symmetry 
requires. The cube has eight similar solid angles—similar, 
that is, in the enclosing planes and plane angles. Con~ 


26 CRYSTALLOGRAPHY. 


sequently the law of full symmetry requires that all should 
have the same planes and the same number of planes; and 
this is the general law for all the forms. This is a conse- 
quence of the equality of the axes and their rectangular in- 
tersections. 

But in some crystalline forms there are only half the 
number of planes which full symmetry requires. In Fig. 
39 a cube is represented with an octahedral plane on half, 
that is, four, of the solid angles. A solid angle having such 


40. 42, 


a plane is diagonally opposite to one without it. The same 
form is represented in Fig. 40, only the cubic faces are the 
smallest ; and in Fig. 41 the simple form is shown which is 
made up of the four octahedral planes. It is a tetrahedron 
or regular three-sided pyramid. If the octahedral faces of 
Fig. 39 had been on the other four of the solid angles of the 
cube, the tetrahedron made of those planes would have 
been that of Fig. 42 instead of Fig. 41. 

Other hemihedral forms are represented in Figs. 43 to 
45. Fig. 43 is a hemihedral form of the trapezohedron, Fig. 








4,p.18; Fig. 44, hemihedral of the hexoctahedron, Fig. 7, or 
a hemi-hexoctahedron; and Fig. 45 is a combination of the 
tetrahedron (plane 1) and hemi-hexoctahedron. 
- In these forms Figs. 41-44, no face has another parallel 
% it; and consequently they are called inclined hemihe- 
rons. 
Fig. 46 represents a cube with the planes of a tetrahexa 


ISOMETRIC SYSTEM. 27 


hedron, as already explained. In fig. 47, the cube has 
only one of the planes 7-2 on each edge, and therefore only 
twelve in all; and hence it affords an example of hemihe- 
drism—a kind that is presented by many crystals of pyrite. 





Fig. 48 is the hemihedral form resulting when these twelve 
planes 7-2 are extended to the obliteration of the cubic 
faces ; and Fig. 49 is another, made of the 50 

other twelve of these planes. Again, in Fig. i 
50,a cube is represented having only three 
out of the six planes of Fig. 22, and this is 
another example of hemihedrism. These 
kinds differ from the inclined hemihedrons 
in having opposite parallel faces, and hence 
they are called parallel hemihedrons. 





4. Internal Structure of Isometric Crystals, or Cleavage. 
-—The crystals of many isometric minerals have cleavage, or 
a greater or less capability of division in directions situated 
symmetrically with reference to the axes. The cleavage 
directions are parallel either to the faces of the cube, the 
octahedron, or the dodecahedron. In galenite (p. 160) 
there is easy cleavage in three directions parallel to the faces 
of the cube ; in fluorite (p. 227), in four directions parallel 
to the faces of the octahedron; in sphalerite (p. 170), in 
six directions parallel to the faces of the dodecahedron. 
These cleavages are an important means of distinguishing 
the species. 

The three cubic cleavages are precisely alike in the ease 
with which cleavage takes place, and in the kinds of surface 
obtained ; and so is it with the four in the octahedral direc- 
tions, and the six in the dodecahedral. Occasionally cleav- 
ages of two of these systems occur in the same mineral ; 
that is, for example, parallel both to the faces of the cube 
and of the octahedron ; but when so, those of one system are 


28 CRYSTALLOGRAPHY. 


much more distinct than those of the other, and cleavage 
surfaces in the two directions are quite unlike as to smooth- 
ness and lustre. 

5. Irregularities of Isometric Crystals—A cube has its 
faces precisely equal, and so it is with each of the forms rep- 


resented in Figs. 2 to 7, p. 18. This perfect symmetry is 
almost never found in actual crystals. 


52. 53. 





A cubic crystal has generally the form of a square prism 
(Fig. 51 a stout one, Fig. 52 another long and slender), or a 
rectangular prism (Fig. 53). In such cases the crystal may 
still be known to be a cube ; because, if so, the kind of sur- 


face and kind of lustre on the six faces will be precisely 
alike; and if there is cubic cleavage it will be exactly 
equal in facility in three rectangular directions; or if there 
is cleavage in four, or six, directions, it will be equal in 





ISOMETRIC SYSTEM. 29 


degres in the four, or the six, directions, and have mutual 
inclinations corresponding with the angles of the octahedron 
or dodecahedron; and thus the crystal will show that it is 
isometric in system. 

The same shortening or lengthening of the crystal often 
disguises greatly the octahedron, dodecahedron, and other 
forms. This is illustrated in the following figures: Fig. 54 
shows the form of the regular octahedron ; 55, an octahe- 
dron lengthened horizontally ; 56, one shortened parallel to 
one of the pairs of faces; 57, one lengthened parallel to 
another pair, the ultimate result of which obliterates two 
of the faces, and places an acute solid angle in place of 
each. The solid is then six-sided, and has rhombic faces 
whose plane angles are 120° and 60°. The following figures 





illustrate corresponding changes in the dodecahedron (Fig. 
58). In Fig. 59 the dodecahedron is lengthened vertically, 
making a square prism with four-sided pyramidal termina- 
tions. In 60, it is shortened vertically. In 61 the dodeca- 
hedron is lengthened obliquely in the direction of an octa- 
hedral axis, and in 62 it is shortened in the same direction, 
making six-sided prisms with trihedral terminations. 


30 CRYSTALLOGRAPHY. 


So again in the trapezohedron there are equally deceptive 
forms arising from elongations and shortenings in the same 
two directions. 

These distortions change the relative sizes of planes, but 
not the values-of. angles. In crystals of the several forms 
represented in Figs. 54 to 57, the inclinations are the same 
as in the regular octahedron. 'There is the same constancy 
of angle in other distorted crystals. 

Occasionally, as in the diamond, the planes of crystals 
are convex; and then, of course, the angles will differ from 
the true angle. Itis important, in order to meet the diffi- 
culties in the way of recognizing isometric crystals, to have 
clearly in the mind the precise aspect of an equilateral tri- 
angle, which is the shape of a face of an octahedron; the 
form of the rhombic face of the dodecahedron; and the 
form of the trapezoidal face of a trapezohedron. With 
these distinctly remembered, isometric crystalline forms 
that are much obscured by distortion, or which show only 
two or three planes of the whole number, will often be 
easily recognized. 

Crystals in this system, as well as in the others, often 
have their faces striated, or else rough with points. This 
is generally owing to a tendency in the forming crystal to 
make two different planes at the same time, 














cube of pyrite with striated faces. As the 
faces of a cube are equal, the striations are 
| alike on all. It will be noted that the stria- 
tions of adjoining faces are at right angles to one another. 
The little ridges of the striated surfaces are made up of 
planes of the pentagonal dodecahedron (Fig. 49, p. 27), and 
they arise from an oscillation in the crystallizing conditions 
between that which, if acting alone, would make a cube, 
and that which would make this hemihedral dodecahedron. 
Again, in magnetite, oscillations between the octahedron 
and dodecahedron produce the striations in Fig. 64. 
Octahedral crystals of fluorite often occur with the faces 
made up of evenly projecting solid angles of a cube, giving 
them rough instead of polished planes. ‘This has arisen 
from oscillation between octahedral and cubic conditions. 
In some cases crystals are filled out only along the diago- 


peat or rather an oscillation between the condi- 
===, tion necessary for making one plane and that 
===] for making another. Tig. 63 represents a 
—— | 








————————— 
———__——J 


TETRAGONAL SYSTEM. at 


nal planes. Fig. 65 represents a crystal of common galt 
of this kind, having pyramidal depressions in place of the 
regular faces. Octahedrons of gold sometimes occur with 








ie SS 


| ass \ 
























wN 





My 
| 


| 


Abe 









































MAGNETITE. COMMON SALT. 


three-sided pyramidal depressions in place of the octahedral 
_ faces. Such forms sometimes result also when crystals are 
eroded by any cause. 


Ii. TETRAGONAL SYSTEM. 


1. Descriptions of Forms——TIn this system (1) the axes 
cross at right angles; (2) the vertical axis is either longer 
or arora than the lateral; and (3) the lateral axes are 
equal. 

The following figures represent some of the crystalline 
forms. They are very often attached by one extremity to 
the supporting rock and have perfect terminating planes 
only at the other. Square prisms, with or without pyra- 
midal terminations, square octahedrons, eight-sided prisms, 
eight-sided pyramids, and especially combinations of these, 
are the common forms. Since the lateral axes are equal, 
the four lateral planes of the square prisms are alike in 
lustre and surface-markings. For the same reason the 
symmetry of the crystal is throughout by fours; that is, 
the number of similar pyramidal planes at the extremity is 
either four or eight; and they show that they are similar 
by being exactly alike in inclination to the basal plane as 
well as alike in lustre. 

There are two distinct square prisms. In one (Fig. 10) 
the axes connect the centres of the lateral faces. In the 


32 CRYSTALLOGRAPHY. 


other (Fig. 12) they connect the centres of the lateral edges. 
In Fig. 11 the two prisms are combined; the figure shows 
that the planes of one truncate the lateral edges of the 


Dette te 


Vs 
. 





other, the interfacial angle between adjoining planes being 
135°. Figs. 2, 3, 4, 7, are of others having planes of both 
DHene In Fig. 13 one prism is represented within the 
other. 

Fig. 14 represents an eight-sided prism, and Fig. 15 a 
f combination of a square prism 

: (7-1) with an eight-sided prism 
(7-2). Another example of this is 
shown in Fig. 4, and also in Fig. 9, 
the planes 2-2 in one, and 7-3 in 
the other. 
_ The basal plane in these prisms 
is an independent plane, because 
the vertical axis is not equal to the 





TETRAGONAL SYSTEM. 30 


lateral, and hence it almost always differs in lustre and 
smoothness from the lateral. 

Like the square prisms, the square octahedrons are in 
two series, one set (Hig. 16) having the lateral or basal 
edges parallel to the lateral axes, and these axes connecting 
the centres of opposite basal edges, and the other (Fig. 17) 
having them diagonal to the axes, these axes connecting 
the apices of the opposite solid angles, as in the isometric 
octahedron. ‘There may be, on the same crystal, faces of 
several octahedrons of these two series, differing in having 
their planes inclined at different angles to the basal plane. 


In Figs. 5 and 7 planes of one of these pyramids terminate 
the prism, and in Figs. 6 and 8 the planes of two. In Figs. 
1 to 3 there are planes of the same octahedron, but com- 
bined with the basal plane O; and in Fig. 4 there are planes 
of two, with O. In Fig. 9 there are planes of the same 
octahedron, with planes of a square prism (7-7), and of an 
eight-sided prism (7-2). In Fig. 18 there is the prism 7-2 
combined with two octahedrons, and the basal plane 0; 
and in 19 the planes of one octahedron with the prism J. 
Fig. 20 represents an eight-sided double pyramid, made 





21. 22. 


\ JA Titi; T 


of equal planes, equally inclined to the base; and Fig. 21, 
the same planes on the square prism 7-7. ‘The small pianes, 
3 





34 CRYSTALLOGRAPHY. 


in pairs, on Fig. 8, are of this kind. In Fig. 22 the small 
planes 3-3 of Fig. 8 occur alone, without planes of the four- 
sided pyramids, and therefore make the eight-sided pyra- 
mid, 3-3. 

The solid made of two such eight-sided pyramids placed 
base to base has the largest number of similar planes 
possible in the tetragonal system, while the largest number 
in the isometric system (occurring in the hexoctahedron) 
is forty-eight. 


2. Positions of the planes with reference to the Axes,—-Let- 
tering of planes. In the prism Fig. 10, the lateral planes are parallel to 
the vertical axis and to one lateral axis, and meet the other lateral axis 
atitsextremity. The expression for it is hence (c standing for the vertical 
axis and a, b for the lateral) ze : 7b : 1a, 7, as before, standing for in- 

finity and indicating parallelism. 

23. For the prism of Fig. 12, the 

-a prismatic planes meet the two 

lateral axes at their extremities, 

and are parallel to the vertical, 

and hence the expression for 

them is ic: 1b:1a. In the an- 

nexed figure the two bisecting 

lines, a -a and 6 -b, represent the 

lateral axes; the line st stands 

for a section of a lateral plane of 

the first of these prisms, it being 

parallel to one lateral axis and meeting the other at its extremity, 
and ad for that of the second, it meeting the two at their extremities. 

In the eight-sided prisms (Figs. 14, 15), each of the lateral planes is 
parallel] to the vertical axis, meets one of the lateral axes at its extrem- 
ity, and would meet the other axis if it were prolonged to two or three 
or more times its length. The line qo, in Fig. 238, has the position of 
one of the eight planes; it meets the axis b at o, or twice its length 
from the centre; and hence the expression for it would be ze : 20: 1a, 
or, since b =a, t¢ : 2:1, which is a general expression for cach of the 
eight planes. ‘Again, ap has the position of one of the cight planes of 
another such prism; and since Op is three times the length of 03, the 
expression for the plane would be t¢:3:1. So there may be other 
cight-sided prisms; and, putting m for any possible ratio, the expres- 
sion 7c:n: lisa gencral one for all eight-sided prisms in the tetra- 
gonal system. 

A plane of the octahedron of Fig. 16 mects one lateral axis at its 
extremity, and is parallel to the other, and it meets the vertical axis ¢ 
at its extremity; its expression is Coy (dropving the letters a 
and b, because these axes are equal) 1¢:7:1. Other octahedrons in 
the same vertical series may have the artic} we longer or shorter 
ae AXIS ¢; that 1 is, there may be the planes 2¢: 7:1, 8¢:7¢:1, 4e:7@: 

1, and so on; or je: 7:1,4¢:7%:1, and so on; or, pain m for any co- 
efficient of c, the expression becomes general, mc: 7: 1. Whenm=0 
the vertical axis is zero, and the plane is the basal plane O of the 





TETRAGONAL SYSTEM. 35 


prism; and when m = infinity, the plane is z¢:7¢:1, or the vertical 
plane of the prism in the same series, 7-2, Fig. 10. 

The planes of the octahedron of Fig. 17 meet two lateral axes at their 
extremities, and the vertical at its extremity, and the expression for 
the plane ishence 1c: 1:1. Other octahedrons in this series will have 
the general expression mc : 1:1, in which m may have any value, not 
a decimal, greater or less than unity, as in the preceding case. When 
in this series m = infinity, the plane is that of the prism ze: 1:1, or 
that of Fig. 12. 

In the case of the double eight-sided pyramid (Figs. 20, 21, 22), the 
planes meet the two lateral axes at unequal distances from the centre; 
and also meet the vertical axis. The expression may be 2c: 2:1, 4c: 
2:1, 5¢: 3:1, and so on; or, giving it a general form, me: 7: 1. 

In the lettering of the planes on figures of tetragonal crystals, the 
first number (as in the isometric and all the other systems) is the co- 
efficient of the vertical axis, and the other is the ratioof the other two, 
and when this ratio is a unit it is omitted. 

The expressions and the lettering for the planes are then as follows: 


Expressions. Lettering. 
. de Bers HAL v-¢ 
@oreuuare prisms,.......... i ae sector ee 
For eight-sided prisms......... 46s wii1 in 
: 1. mesar1 m-t 
For octahedrons............ Pere Le 2, 
For double eight-sided pyramids, mc:n:1 m-n 


The symbols are written without a hyphen on the figures of crystals. 
On Fig. 14, the plane ¢-n is that particular ¢-n in which n = 2, or 
7-2. In Fig. 21 the planes of the double eight-sided pyramid, m-n, have 
m =1 and n = 2 (the expression being 1: 2:1), and hence it is let- 
tered 1-2. In Fig. 8 and in Fig. 22 it is the one in which m= 3 and 
nm = 38 (the expression being 3: 3: 1), and hence the lettering 3-3. 

The length of the vertical axis c may be calculated as follows, pro- 
vided the crystal affords the required angles: 

Suppose, in the form Fig. 18, the inclination of Oon plane 1-7 to 
have been found to be 180°, or of 7-2 on the same plane, 140° (one fol- 
lows from the other, since the sum of the two, as has been ; 
explained, is necessarily 270°). Subtracting 90°, we have ra. 
40° for the inclination of the plane on the vertical axis ¢, D 
or 50° for the same on the lateral axis a, or the basal 
section. In the right-angled triangle, OBC, the angle 
OBC equals 40°. If OC be taken as a = 1, then BC will 
be the length of the vertical axis c; and its value may be 
obtained by the equation cot 40° = BC, or tan 50° = BC. B 

On Fig. 18 there is a second octahedral plane, lettered 
4-7, and it might be asked, Why make this plane 4-2, 
instead of 1-7? The determination on this point is 
more or less arbitrary. It is usual to assume that 5 C 
plane as the unit plane in one or the other series of 
octahedrons (Fig. 16 or Fig. 17) which is of most common occur- 
rence, or that which will give the simplest symbols to the crystalline 


36 CRYSTALLOGRAPHY. 


forms of a species; or that which will make the vertical axis nearest 
to unity; or that which corresponds to a cleavage direction. 

The value of the vertical axis having been thus determined from 1-7, 
the same may be determined in like manner for 4-2 in the same figure 
(Fig. 18). The result would be a value just half that of BC. Or if 
there were a plane 2-7, the value obtained would be twice BC, or BD 
in Fig. 24; the angle ODC-+ 90° would equal the inclination of O on 
2-2. So for other planes in the same vertical zone, as 3-2, 4-2, or any 
plane m-7. 

If there were present several planes of the series m-?, and their in- 
clinations to the basal plane O were known, then, after subtracting 
from the values 90°, the cotangents of the angles obtained, or the 
tangents of their complements, will equal m in each case; that is, the 
tangents (or cotangents) will vary directly with the value of m. The 
logarithm of the tangent for the plane 1-2, added to the logarithm of 
2, will equal the logarithm of the tangent for the plane 2-2, and so on. 

The law of the tangents for this vertical zone m-7 holds for the planes 
of all possible vertical zones in the tetragonal system. Further, if 
the square prism were laid on its side so that one of the lateral planes 
became the base, and if zones of planes are present on it that are ver- 
tical with reference to this assumed base, the law of the tangents still 
holds, with only this difference to be noted, that then one of the late- 
ral axes is the vertical. It holds also for the orthorhombic system, no 
matter which of the diametral planes is taken for the base, since all 
the axial intersections are rectangular. It holds for the monoclinic 
system for the zone of planes that lies between the axes c and d and 
that between the axcs a and 2, since these axes meet at right angles, 
but not for that between ¢ and a, the angle of intersection here being 
oblique. It holds for all vertical zones in the hexagonal system, since 
the basal plane in this system is at right angles to the vertical axis. 
But it is of no use in the ¢riclinie system, in which all the axial inter- 
sections are oblique. 

The value of the vertical axis ¢ may be calculated also from the in- 
clination of Oon1, or of Jon 1. See Fig. 2, and compare it with Fig. 
17. Ifthe angle Jon 1 equals 140°, then, after subtracting 90°, we 
have 50° for the basal angle in the triangle OCR, Fig. 24; or for half 
the interfacial angle over a basal edge—edge Z—in Fig. 17. The value 
of ¢ may then be calculated by means of the formula 


c= tan 34Z 1/4, 


by substituting 50° for $7 and working the equation. 
For any octahedron in the series m, the formula is 


me = tan 4Z 4/4 
Z being the angle over the basal edge of that octahedron. If m= 2, 
then c= 4 (tan $7 4/4). Further, m= (tan 4Z /4)+ ¢. 


The interfacial angle over the terminal edge of any octahedron m 
may be obtained, if the value of ¢ is known, by the formulas 


me = cot € cos € = cot 1X 


X being the desired angle (Fig. 17). The same for any octahedron m-¢ 
may be calculated from the formulas 


TETRAGONAL SYSTEM. 37 


me = cot € cos é=cosiY 2 


Y being the desired angle (Fig. 16). 

For other methods of calculation reference may be made to the 
“ Text-book of Mineralogy,” or to some other work treating of mathe- 
matical crystallography. 

3. Hemihedral Forms—Among the hemihedral forms 
under the tetragonal system there is a tetrahedron, called a 
sphenoid (Fig. 25 or 26), and also forms in which only half 
of the sixteen planes of the double eight-sided pyramid, or 
half the eight planes of an eight-sided prism—those alter- 


WAV G 


nate in position—are present (Figs. 27, 28). In Fig. 27 the 
absent planes are those of half the pairs of planes; and in 
Fig. 28 they include one of each of the pairs, as will be seen 
on comparing these figures with Fig. 21. 

4. Cleavage.—In this system cleavage may occur parallel 
to the sides of either of the square prisms; parallel to the 
basal plane; parallel to the faces of a square octahedron; 
or in two of these directions at the same time. Cleavage 
parallel to the base and that parallel to a prism are never 
equal, so that such prisms need not be confounded with 
distorted cubes. 

5. Irregularities in Crystals—The square prisms are 
very often rectangular instead of square, and so with the 
octahedrons. But, as elsewhere among crystals, the angles 
remain constant. When forms are thus distorted, the four 
prismatic planes will have lke lustre and surface markings, 
and thus show that the faces are normally equal and the 
lateral axes therefore equal. If the plane truncating the 
edge of a prism makes an angle of precisely 135° with the 
faces of the prism, this is proof that the prism is square, or 
that the lateral axes are equal, since the angle between a 
diagonal of a square and one of its sides is 45°, and 135° is 
the supplement of 45°. 

6. Distinctions—The tetragonal prisms have the base 


38 CRYSTALLOGRAPHY. 


different in lustre from the sides, and planes on the basal 
edges different in angle from those on the lateral, and thus 
they differ from isometric forms. The lateral edges may 
be truncated, and the new plane will have an angle of 135° 
with those of the prism, in which they differ from ortho- 
rhombic forms, while like isometric. The extremities of the 
prism, if it have any planes besides the basal, will have 
them in fours or eights, each of the four, or of the eight, 
inclined to the base at the same angle. When there is any 
cleavage parallel to the vertical axis, it is alike in two di- 
rections at right angles with one another. The lateral 
planes of either square prism are alike in lustre and mark- 
Ings. 
III. ORTHORHOMBIC SYSTEM. 

1. Descriptions of Forms.——The crystals under the or- 
thorhombic system vary from rectangular to rhombic prisms 
and rhombic octahedrons, and include various combinations 
of such forms. Figs. 1 to 7 are a few of those of the spe- 
cies barite, and Figs. 8 to 10 of crystals of sulphur. 





BARITE. 


Fig. 11 represents a rectangular prism (diametral prism), 
and Fig. 12 a rhombic prism, each with the axes. The 
axes connect the centres of the opposite planes in the for- 
mer; but in the latter the lateral axes connect the centres 
of the opposite edges. Of the two lateral axes the longer 
is called the macrodiagonal, and the shorter the brachydi- 


ORTHORHOMBIC SYSTEM. 39 


agonal. 'The vertical section containing the former is the 
macrodiagonal section, and that containing the latter, the 
brachydiagonal section. 

In the rectangular prism, Fig. 11, only opposite planes 
are alike, because the three axes are unequal. Of these 
planes, that opposite to the larger lateral axis is called the 
macropinacoid, and that opposite the shorter the drachy- 
pinacoid (from the Greek for long and short, and a word 
signifying board or table). Each pair—that is, one of these 
planes and its opposite—is called a hemiprism. 

In the rhombic prism, Fig. 12, the four lateral planes 
are similar planes. But of the four lateral edges of the 


12. 
oF 





prism two are obtuse and two acute. Fig. 13 represents a 
combination of the rectangular and rhombic prisms, and 
illustrates the relations of their planes. Other rhombic 
prisms parallel to the vertical axis occur, differing in inter- 
facial angles, that is, in the ratio of the lateral axes. 

Besides vertical rhombic prisms, there are also horizontal 
prisms parallel to each lateral axis, a and b. In Fig. 2 the 
narrow planes in front (lettered $7) are planes of a rhombic 
prism parallel to the longer of the lateral axes, and those 
to the right (17) are planes of another parallel to the shorter 
lateral axis. In Fig. 6 the planes are those of these two 
horizontal prisms. Such prisms are called also domes, be- 
cause they have the form of the roof of a house (domus in 
Latin meaning house). In Fig. 3 these same two domes 
occur, and also the planes (lettered J) of a vertical rhom- 
bic prism. Of these domes there may be many, both in 
the macrodiagonal and the brachydiagonal series, differing 
in angle (or in ratio of the two intersected axes). Those 
parallel to the longer lateral axis, or the macrodiagonal, 
are called macrodomes ; and those parallel to the shorter, 
or brachydiagonal, are called brachydomes. 

A rhombic octahedron, lettered 1, is shown in Fig. 8; a 
combination of two, lettered 1 and 4, in Fig. 9; and a com- 


40 CRYSTALLOGRAPHY. 


bination of four, lettered 1, 4, 4, 4, in Fig. 10. This last 
figure contains also the planes J, or those of a vertical 
rhombic prism; the planes 1-2, or those of a dome parallel 
to the longer lateral axis; the planes 1-7, or those of a dome 
parallel to the shorter lateral axis; the plane O, or the basal 
plane; the plane 7-7, or the _brachypinacoid; and also a 
. rhombic octahedron lettered 1-3. , 


2. Positions of Planes. Lettering of Crystals.—The nota- 
tion is, ina general way, like that of the tetragonal system, but with dif- 
ferences made necessary by the inequality of the lateral axes. The let- 
ters for the three are written ¢: 6: a; 6 being the longer lateral and d the 
shorter lateral. In place of the square prism of the tetragonal system, 7-2, 
there are the hemiprisms 7-7 and 7-2, or_the macropinacoid and brachy- 
pinacoid, having the expressions ¢c: 2b: 1@ and t¢: 16: 7d. The form 
lis the rhombic prism, having the expression 7c: 16: 1d, correspond- 
ing to the square prism J in the tetragonal system. The planes 7-7 or 
i-% are other rhombic vertical prisms, the former corresponding to Zc : 
mo: 1d, the other to 7c: 18: nd. If n= 2, the plane is lettered either 
i-2 or 7-2. The plane 1-8 has the expression 1c: 1b:3¢. m-% and 
m-h comprise all possible rhombic prisms and octahedrons, and cor- 
respond to the expressions mc: 7b: 1d and mec :1b: nd. When m= 
infinity they become 7-% and ¢-7, or expressions for vertical rhombic 
prisms; when 7 = infinity they become m-2 and m-?, or expressions 
for macrodomes and brachydomes. 

The question which of the three axes should be taken as the verti- 
cal axis is often decided by reference simply to mathematical con- 
venience. Sometimes the crystals are prominently prismatic only in 
one direction, as in topaz, and then the axis in this direction is made 
the vertical. In many cases a cleavage rhombic prism, when there is 
one, is made the vertical, but exceptions to this are numerous. There 
is also no general rule for deciding which octahedron should be taken 
for the unit octahedron. But however decided, the axial relations for 
the planes will remain essentially the same. In Fig. 10, had the plane 
lettered + been made the plane 1, then the series, instead of being as it 
is in the figure, 1, 4, +, 4, would have been 2, 1, 2, 2, in which the 
mutual axial relations are the same. 

The relative values of the axes in the orthorhombic system may be 
calculated in the same way as that of the vertical axis in the tetra- 
gonal system, explained on page 35. The law of the tangents, as 
stated on page 36, holds for this system. 


3. Hemihedral Forms.—Hemihedral forms are not com- 
mon in this system. Some of those so considered have 
been proved to owe the apparent hemihedrism to their 
being of the monoclinic system, as in the case of datolite 
and two species of the chondrodite group. In a few kinds, 
as, for example, calamine, one extremity of a crystal differs 


MONOCLINIC SYSTEM. 41 


in its planes from the other. Such forms are termed hemi- 
morphic, from the Greek for half and form. ‘They become 
polar electric when heated, that is, are pyroelectric, show- 
ing that this hemimorphism is connected with polarity in 
the crystal. 

4, Cleavage.—Cleavage may take place in the direction 
of either of the diametral planes (that is, either face of the 
rectangular prism) ; but it will be different in facility and 
in the surface afforded for each. In anhydrite, however, 
the difference is very small. Cleavage may also occur in 
the direction of the planes of a rhombic prism, either alone 
or in connection with cleavage in other directions. It also 
sometimes occurs, as in sulphur, parallel to the faces of a 
rhombic octahedron. 

5. Irregularities in Crystals.—The crystals almost never 
correspond in their diametral dimensions with the cal- 
culated axial dimensions. They are always lengthened, 
widened, shortened, or narrowed abnormally, but without 
affecting the angles. Examples of diversity in this kind of 
_ distortion are given in I’igs. 1 to 7, of barite. 

6. Distinctions—In the orthorhombic system the angle 
135° does not occur, because the three axes are unequal. 
There are pyramids of four similar planes in the system, 
but never of eight; and the angles over the terminal edges 
of the pyramids are never equal as they are in the tetra- 
gonal system. The rectangular octahedron of the ortho- 
rhombic system is made up of two horizontal prisms, as 
shown in Fig. 6, and is therefore not a simple form; and 
it differs from the octahedron of the tetragonal system cor- 
responding to it (Fig. 16, p. 33) in having the angles over 
the basal edges of two values. 


IV. MONOCLINIC SYSTEM. 


1. Descriptions of Forms.—In this system the three axes 
are unequal, as in the orthorhombic system; but one of 
the axial intersections is oblique, that between the axis a 
and the vertical axis c. The following examples of its 
crystalline forms, Figs. 1 to 6, show the effect of this ob- 
liquity. On account of it the front or back planes above 
and below the middle in these figures differ, and the ante- 


42 CRYSTALLOGRAPHY. 


rior and posterior prismatic planes are unequally inclined 
to a basal plane. 


1. a 4. 
j 


The axes and their relations are illustrated in Figs. 7 and 
8. Fig. 7 represents an oblique rectangular prism, and 
Fig. 8 an oblique rhombic. ‘The former is the diametral 
prism, like the rectangular of the orthorhombic system. 
he axes connect the centres of the opposite faces, and the 
planes are of three distinct kinds, being parallel to unlike 
axes and diametral sections. In the latter, as in the rhom- 
bic prism of the orthorhombic system, the lateral axes con- 
nect the centres of the opposite sides. Moreover, this 
rhombic prism may be reduced to the rectangular by the 
removal of its edges by planes parallel to the lateral axes. 





MONAZITE. MIRABILITE. 


The axis a, or the inclined lateral axis (inclined at an 
oblique angle to the vertical axis c), is called the clinodiago- 


MONOCLINIC SYSTEM. 43 


nal ; and the axis 0, which is not inclined, the orthodiago- 
nal (from the Greek for right, or rectangular). The ver- 
tical section through the for- 
mer is called the clinodiago- 
mal section; it is parallel to 
the plane 7-2 (Figs. 1-6). 
The vertical section through 
the latter is the orthodiago- 
nal section ; it is parallel to 
planes 7-7. Owing to the ob- 
lique angle between a and c, the planes above a differ in 
their relations to the axes from those below, and hence 
Bees the difference in the angle they make with the basal 
plane. 

The halves of a crystal either side of the clinodiagonal 
section—the vertical section through a and c—are alike in 
all planes and angles. Another important fact is this: that - 
the plane 7-2, or that parallel to the clinodiagonal section, 
is at right angles not only to O and 1-7, but to all planes in 
the zone of O and 7-7; that is, in the clinodiagonal zone ; 
and this is a consequence of the right angle which axis 6 
makes with both axis c and axisa. ‘The plane 7-7 is called 
the orthopinacoid, it being parallel to the orthodiagonal ; 
and the plane 7-2, the clinopinacoid, it being parallel to the 
clinodiagonal. 

Vertical rhombic prisms have the same relations to the 
lateral axes as in the orthorhombic system. Domes, or 
horizontal rhombic prisms, occur in the orthodiagonal zone, 
because the vertical axis ¢ and the orthodiagonal 4 make 
right angles with one another. In Fig. 6 the planes 1-?, 
2-2, belong to two such domes. They are called clinodomes, 
because parallel to the clinodiagonal. 

In the clinodiagonal zone, on the contrary, the planes 
above and below the basal plane differ, as already stated, 
and hence there can be no orthodomes ; they are hemiortho- 
domes. Thus, in Fig. 6, 4-7, 1-7 are planes of hemiortho- 
domes above 7-7, and — 4-7 is a plane of another of different 
angle below 7-7. The plane, and its diagonally opposite, 
make the hemiorthodome. 

The octahedral planes above the plane of the lateral axes 
also differ from those below. ‘Thus, in Figs. 5 and 6, the 
planes 1, 1 are, in their inclinations, different planes from 


7. 8. 





44 CRYSTALLOGRAPHY. 


the planes — 1, — 1; so in all cases. Thus there can be no 
monoclinic octahedrons—only hemi- 
octahedrons. An oblique octahe- 
dron is made up of two sets of 
planes; that is, planes of two hemi- 
octahedrons. Such an octahedron 
? may be modelled and figured, but 
it will consist of two sets of planes: 
one set including the two above the 
basal section in front and their 
diagonally opposites behind (Fig. 
9), and ‘he other set including the two below the basal sec- 
tion and their diagonally opposites (Fig. 10). 

A hemioctahedron, since it consists of only four planes, 
is really an obliquely placed rhombic prism, and very fre- 
quently they are so lengthened as to be actual prisms. 





2. Positionsof Planes, Lettering of Crystals.—On account 
of the obliquity of the crystals, the planes above and below the basal 
section require a distinguishing mark in their lettering, as well as in 
the mathematical expressions for them. One set is made minus and 
the other plus. The plus sign is omitted in the lettering. In Fig. 7 
there are above the basal section (or above 7-2) the planes 1-2, 4-7, 1, 4, 
but below it, —4-¢, —1. The plus planes are those opposite the acute 
intersection of the basal and orthodiagonal sections, and the minus 
those opposite the obtuse. No signs are needed for planes of the 
clinodiagonal section, since they are alike both above and below the 
basal section. 

The distinction of longer and shorter lateral axis is not available in 
this system, since cither may be the clinodiagonal. The distinction 
of clinodiagonal and orthodiagonal planes is indicated by a grave 
accent over the number or letters referring to the clinodiagonal. The 
lettering for the clinodomes on Fig. 6 is {4 2, 2-i—the 2 (initial of infi- 
nite, with the accent) signifying par rallelism to the clinodiagonal. The 
hemioctahedrons, 1, 2, etc., need no such mark, as the expression for 
them is le: 1d: 1d, 2¢:10: ‘1a, the planes having a unit ratio for d@ 
and 6. But the plane 2-8, in Fig. 5, requires it, its expression being 
2c: 1b: 2d; the fact that the last 2 refers to the clinodiagonal is 
indicated by the accent. If it referred to the orthodiagonal, “that is, 
if the expression for the plane were 2c: 20: 1d, it would be written 
2-2 without the accent. 


3. Cleavage.—Cleavage may be basal, or parallel to either 
of the other diametral sections, or parallel to a vertical 
rhombic prism, or to the planes of a hemioctahedron; or 
_to the planes of a clinodome, or to that of a hemiortho- 
dome. If occurring in two or more directions in any 


TRICLINIC SYSTEM. 45 


species it is always different in degree in each different 
direction, as in all the other systems. 

4, Irregularities—Crystals of this system may be elon- 
gated abnormally in the direction of either axis, and any 
diagonal. ‘The hemiorthodomes may be in aspect the bases 
of prisms, and the hemioctahedrons the sides of prisms. 
Which plane in the zone of hemiorthodomes should be 
made the base, and which in the series of hemioctahedrons 
should be assumed as the fundamental prism determining 
the direction of the vertical axis, is often decided differ- 
ently by different crystallographers. Convenience of math- 
ematical calculation is often the principal point referred to 
in order to reach a conclusion. 


VY. TRICLINIC SYSTEM. 


1, Descriptions of Forms.—In the triclinic system the 
three axes are unequal and their three intersections are 
oblique, and consequently there are never more than two 
planes of a kind; that is, planes having the same inclina- 
one to either diametral section. The following are exam- 
ples: 





AXINITE. ANORTHITE. AMBLYGONITH. 


The difference in angle from monoclinic forms is often 
very small. This is true in the Feldspar family. Fig. 2, 
of the feldspar called anorthite, is very similar in general 
form to Fig. 4, of orthoclase, which is monoclinic. This 


46 CRYSTALLOGRAPHY. 


is still more strikingly seen on comparing Fig. 4 with Fig. 
5 representing a crystal of oligoclase, another one of the 
triclinic feldspars. The planes on the two are the same 


4, 





ORTHOCLASE. OLIGOCLASE. 


with one exception; but there is this difference, that in 
orthoclase, as in all monoclinic crystals, the angle between 
the planes O and 7-2 (the two directions of cleavage) is 90°; 
and in oligoclase and other triclinic feldspars it is 3° to 
6° from 90°, being in oligoclase 93° 50’, and in anorthite 
94° 10’. This difference in angle involves oblique inter- 
sections between the axes ) and c, and ¢ and a, which are 
rectangular in monoclinic forms. ‘There is a similarly — 
close relation between the triclinic form of rhodonite and 
that of pyroxene, and a resemblance also in composition. 

The diametral prism in this system is similar to Fig. 7 
on page 43, under the monoclinic system, but differs in 
having the planes all rhomboidal instead of part rectangu- 
lar. ‘The form corresponding to the oblique rhombic prism 
of the monoclinic system (Fig. 8, p. 43) also has rhom- 
boidal instead of rhombic planes; moreover, the two pris- 
matic planes have unequal inclinations to the vertical dia- 
metral section, and are therefore dissimilar planes. The 
prism, consequently, is made of two hemiprisms, and the 
basal plane is another, making in all three hemiprisms. 

2. Cleavage.—Cleavage takes place independently in dif- 
ferent diametral or diagonal directions. In the triclinic 
feldspars it conforms to the directions in orthoclase, with 
only the exception arising from the obliquity above ex- 
plained. 


HEXAGONAL SECTION OF HEXAGONAL SYSTEM. 47 


VI. HEXAGONAL SYSTEM. 


This system is distinguished from the others by the 
character of its symmetry—the number of planes of a kind 
around the vertical axis being a multiple of 3. The num- 
ber of /ateral axes is hence 3. It is related to the tetra- 
gonal system in having the lateral axes at right angles to 
the vertical and equal, and is hence like it also in the opti- 
cal characters of its crystals. Its hexagonal prismatic form 
approaches orthorhombic crystals in the obtuse angle 
(120°) of the prism, some orthorhombic crystals having an 
angle of nearly 120°. 

Under this system there are two sections: 

1. The HEXAGONAL SECTION, in which the number of 
planes of a kind around each vertical axis above or below 
the basal section is 6 or 12. 

2. The RHOMBOHEDRAL SECTION, in which the number 
of planes of a kind around each half of the vertical axis, 
above or below the basal section, is 3 or 6; and, in addition, 
the planes above alternate in position with those below. 
The forms are mathematically hemihedral to the hexago- 
nal, but not so in their real nature. 


I. HEXAGONAL SECTION. 


1, Description of Forms.—Figs. 1 to 3 represent some of 





MIMETITE. ~ BERYL. APATITE, 


the forms under this section. Figs. 2 and 3 show only one 
extremity; and such crystals are seldom perfect at both. 


48 CRYSTALLOGRAPHY. 


All exhibit well the symmetry dy sizes which characterizes 
this section of the hexagonal system. 





Prisms. Under this system there are two hexagonal 
prisms and a number of occurring twelve-sided prisms. 
Fig. 4 represents one of the hexagonal prisms, with its 
axes—the three lateral connecting the centres of the oppo- 
site edges. The lateral angles of the prism are 120°. If 
the lateral edges of this prism are truncated, as in the fig- 
ure of apatite (Fig. 3), the truncating planes, 7-2, are the 
lateral faces of another similar hexagonal prism, in which, 
as the relations of the two show, the lateral axes connect 
the centres of the opposite lateral faces. This prism is 
represented in Fig. 5. 

The lateral edges of the hexagonal prisms occur some- 
times with two similar planes on each edge, and these 
planes, when extended to the obliteration of the hexagonal 

prism, make a ¢welve-sided prism. 

These two planes are seen in 
zeal he , Fig. 8, along with the planes J 
rea ies (eet oa ae | of the hexagonal prism, and 1 of 
sides the basal plane O. 

Double pyramids. ‘The double 
pyramids are of three kinds: (1) A series of six-sided, whose 
planes belong to the same vertical zone with the planes J. 
The planes of two such pyramids (lettered.1, 2) are shown 
in Figs. 1 and 2, three of them in Fig. 3 (lettered 4, 1, 2), 
and one in Fig. 7, and .one such double pyramid, without 
combination with other planes, in Fig. 6. (2) A series of 
six-sided double pyramids whose planes are in the same 
vertical zone with 7-2, examples of which occur on Fig. 2 
(plane 2-2) and on Fig. 3 (planes 1-2, 2-2, 4-2). The form of 





TRIDYMITE. 


HEXAGONAL SECTION OF HEXAGONAL SYSTEM. 49 


this double pyramid is like that represented in Fig. 6, but 
the lateral axes connect the centres of the basal edges. The 
double six-sided pyramid is sometimes called a quartzoid, 
because it occurs in quartz. (3) T’welve-sided double pyra- 
mids. ‘Iwo planes of such a pyramid are shown on a hexa- 





gonal prism in Fig. 9, also in Fig. 2 (the planes 3-3), and 
the simple form consisting of such planes in Fig. 10—a 
form called a derylloid, as the planes are common in beryl. 
In Fig. 11 the planes 1 belong to a double six-sided pyra- 
mid ; and those next below (of which three are lettered W) 
to a double twelve-sided pyramid. 


2. Lettering of Crystals.—The prism of Fig. 5 is lettered 72, 
because it is parallel to the vertical axis, and has the ratio of 1 : 2 be- 
tween two lateral axes. This is shown in the annexed figure, which 
represents the hexagonal outline of 
the prism 7-2 circumscribing that of 
the prism J. The plane 7-2 is produced 
to meet axis a, which it does when a 
is extended to teice tts length; whence 
the ratio for the axes a, a, is 1: 2. 

The numbers 1, 2, on the double 
hexagonal pyramids in Fig. 1 indicate 
the relative lengths of the vertical 
axis of the two pyramids, they having 
the same 1 : 1 ratio of the lateral axes; A i2 CB 
and so in Figs. 2, 3, and others. 

The lettering on the pyramids of the other series in Fig, 3, 1-2, 2-2, 
4-2, indicates, by the second figure, that the planes are in the same 
vertical zone with the prismatic plane 7-2, and by the first figure the 
relative lengths of the vertical axes. 

In the twelve-sided prisms such ratios as 7-3, 7-4, 7% occur. The 
fraction in any case expresses the ratio of the lateral axes for the par- 
ticular planes. The double twelve-sided pyramids have the ratios 3-3 


t 





50 CRYSTALLOGRAPHY. 


(Fig. 2), 4-4, and others. Both in these forms and the twelve-sided 
prisms, the second figure in the lettering, expressing the ratio of the 
lateral axes, has necessarily a value between 1 and 2. 


3. Hemihedral Forms.—Fig. 13 represents a crystal of 
apatite in which there are two sets of planes, 0 (= 5-3) and 
o’ (=4-4) which are hemi- 
18. hedral, only half of the full 
number of each o existing, in- 
stead of all. This kind of hemi- 
hedrism consists in the suppres- 
sion of an alternate half of the 
planes in each pyramid of the 
double twelve-sided pyramid 
(Fig. 10); and in the suppressed 
planes of the upper pyramid be- 
ing here directly over those sup- 
: ressed in the lower pyramid. 
Gees if the student will hei over 
half the planes alternately of the two pyramids in Fig. 10, 
putting the shaded planes above directly over those below, 
he will understand the nature of the hemihedrism. In 
some hemihedral forms the suppressed planes of the upper 
pyramid alternate with those of the lower; but this kind 
occurs only in the rhombohedral section of the hexagonal 
system. 

4, Cleavage.—Cleavage is usually basal, or parallel to a 
six-sided pyramid, Sometimes there are traces of cleavage 
parallel to the faces of a six-sided pyramid. 

5. Irregularities of Crystals. — 
Distortions sometimes disguise 
greatly the real forms of hexagonal 
crystals by enlarging some planes 
at the expense of others. ‘This is 
illustrated in Fig. 14, represent- 
ing the actual form presented by 
acrystal having the planes shown 
in Fig. 13. Whenever in a prism 
the prismatic angle is exactly 120° 
or 150°, the form is almost al- 
ways of the hexagonal system. 











RHOMBOHEDRAL SECTION OF HEXAGONAL SYSTEM. 51 


2. RHOMBOHEDRAL SECTION. 


1. Descriptions of Forms.—The following figures, 1 to 17, 
represent rhombohedral crystals, and all are of one mineral, 
calcite. ‘They show that the planes of either end of the 
crystal are in threes, or multiples of threes, and that those 
above are alternate in position with those below. ‘There is 


rr 


12. 





FIGURES OF CRYSTALS OF CALCITE, 


one exception to this remark, that of the horizontal or basal 
plane O, in Figs. 8, 11, 13. 

The simple forms include : 

1. Rhombohedrons, Figs. 1 to 6. These forms are in- 
cluded under six equal planes, like the cube, but these 
planes are rhombic; and instead of having twelve rectangu- 
lar edges, they have six obtuse edges and six acute. 

2. Scalenohedrons, Fig. 7%. Scalenohedrons are really 
double six-sided pyramids; but the six equal faces of each 
extremity of the crystals are scalene triangles, and are ar- 
ranged in three pairs; moreover, the pairs above alternate 
with the pairs below; the edges in which the pairs above 
and below meet—that is, the basal edges—make a zigzag 
around the crystal. 

3. Hexagonal prisms, I, Fig. 8. Regular hexagonal 
prisms, having the angle between adjoining faces 120°. 

A rhombohedron has two of its solid angles made up of 


on CRYSTALLOGRAPHY. 


three equal plane angles. When in position the apex of one 
of these solid angles is directly over that of the other, as in 


14. 15. 16. 





FIGURES OF CRYSTALS OF CALCITE. 


Figs. 1 to 6, and also in Fig. 18, and the line connecting 
the apices of these angles (Fig. 18) is called the vertical 
axis. In this position the rhombohedron has six terminal 


21. 





edges, three above and three below, and six lateral edges. 
As these lateral edges are symmetrically situated around the 
centre of the crystal, the three lines connecting the centres 
of opposite basal edges will cross at angles of 60°. These 
lines are the lateral axes of the rhombohedron, and they 
are at right angles to the vertical axis. It is stated on page 
45 that rhombohedral forms are, from a mathematical point 
of view, hemihedral under the hexagonal system. The 
rhombohedron, which may be considered a double three- 
sided pyramid, is hemihedral to the double six-sided pyra- 
mid. Fig. 19, representing the latter form, has its alternate 
faces shaded ; suppressing the faces shaded, the form would 
be that of Fig. 18; and suppressing, instead of these, the 


RHOMBOHEDRAL SECTION OF HEXAGONAL SYSTEM. 53 


faces not shaded, the form would be that of another rhom- 
bohedron, differing only in position. 'The two are distin- 
guished as plus and minus rhombohedrons. They are com- 
bined in Figs. 20, 21, forms of quartz. Rhombohedrons 
vary greatly in the length of the vertical axis with reference 
to the lateral. Figs. 1, 2, 3, and 18 represent crystals with 
the vertical axis short, and Figs. 4, 5, 6 others with a long 
vertical axis. In the former the angle over a terminal 
edge is obtuse or over 90°, and that over a lateral, acute ; 
‘and in the latter the reverse is the case, the angle over the 
terminal edges being less than 90°; the former are called 
obtuse rhombohedrons, and the latter acute. 

The cube placed on one solid angle, with the diagonal 
between it and the opposite solid angle vertical, is, in fact, 
a rhombohedron intermediate between obtuse and acute 
rhombohedrons, or one of 90°—the edges that are the ter- 
minal in this position, and those that are the lateral, being 
alike rectangular edges. Lig. 3 has nearly the form of a 
cube in this position. 

The relation of one series of scalenohedrons to the 
rhombohedron is illustrated in Fig. 22. 

This figure represents a rhombohedron 22. 

with the lateral edges bevelled. ‘These 
bevelling planes are those of a scalenohe- fie 
dron, and the outer lines of the same fig- ALS 
ure show the form of that scalenohedron fo ox 
which is obtained when the bevelment is 
continued to the obliteration of the rhom- 
bohedral planes. Fig. 14 represents this 
scalenohedron with the rhombohedral 
planes much reduced in size. Other sca- 
lenohedrons result when the terminal 
edges are bevelled, and still others from 
pairs of planes on the angles of a rhombo- 





hedron. eb as 
The scalenohedron is hemihedral to Ly 

the twelve-sided double pyramid (Fig. 23). Lif 
In the hexagonal system the three ver- V 


tical axial planes divide the space about 

the vertical axis into six sectors (Fig. 12, p. 50). The 
twelve-sided double pyramid has in each pyramid a pair of 
faces for each sector; that is, six pairs for each pyramid. 
If now the three alternate of these pairs in the lower pyra- 


54. CRYSTALLOGRAPHY. 


mid, and those in the upper pyramid alternate with these (the 
shaded in Fig. 23), were enlarged to the obliteration of the 
rest of the planes, the resulting form would 
be a scalenohedron—a solid with three 
pairs of planes to each pyramid instead of 
six. Such is the mathematical relation of 
the scalenohedron to the twelve-sided 
double pyramid. If the faces enlarged 
were those not shaded in Fig. 23, another 
scalenohedron would be obtained which 
would be the mins scalenohedron, if the 
other were designated the plus. 

Fig. 8 shows the relations of a rhombo- 
hedron to a hexagonal prism. ‘The planes £& replace three 
of the terminal edges at each base of the prism, and those 
above alternate with those below. ‘The extension of the 
planes R to the obliteration of those of the prismatic 
planes, J, and that of the basal plane O, would produce the 
rhombohedron of Fig. 1. Figs. 9 and 10 represent the 
same prism, but with terminations made by the rhombo- 
hedron of Fig. 2. 

By comparing the above figures, and noting that the 
planes of similar forms are lettered alike, the combinations 
in the figures will be understood. Fig. 16 is a combination. 
of the planes of the fundamental rhombohedron R&, with 
those of another rhombohedron 4, and of two scalenohedrons 
1l'and 1°. Fig. 17 contains the planes of the rhombohe- 
dron —4, with those of the scalenohedron 1°, and those of 
the prism 7. These figures, and Figs. 14, 22, have the 
fundamental rhombohedron revolved 60° from the position 
in Fig. 1, so that two planes # are in view above instead 
of the one in that figure. 





2. Lettering of Figures.—F¥igs. 1 to 6, representing rhombo- 
hedrons of the species calcite, are lettered with numerals, excepting 
Fig. 1. In Fig. 1 the letter & stands for the numeral 1, and the 
numerals on the others represent the relative lengths of their vertical 
axes. the lateral being equal. In Fig. 4 the vertical axis is twice that 
in Fig. 1; in Fig. 6 thirteen times; and in Fig. 15 the planes lettered 
16 are those of a rhombohedron whose vertical axis is sixteen times 
that of Fig. 1. The rhombohedrons of Figs. 1, 5, 6, and 15 are plus 
rhombohedrons; that is, they are in the same vertical series; while 2 
and 3 are minus rhombohedrons, as explained above. The rhombo- 
hedron, when its vertical axis is reduced in length to zero, becomes 
the single basal plane lettered O in the series. If, on the contrary, 
the vertical axis of the rhombohedron is lengthened to infinity, the 


RHOMBOHEDRAL SECTION OF HEXAGONAL SYSTEM. 55 


faces of the rhombohedron become those of a six-sided prism. This 
last will be seen from the relations of the planes & to J on Fig. 8, and 
from the approximation to a prismatic form in the planes 16 of Fig. 
15. For an explanation of the lettering of other planes on rhombo- 
"havea bia reference must be made to the ‘‘ Text-Book of Miner- 
alogy. 

3. Hemihedrism. Tetartohedrism.—Hemihedrism occurs 
among rhombohedral forms, similar to that in Fig. 13, 
page 50, except that the suppressed planes of one pyramid 
are alternate with those of the other. 
One of these is represented in Fig. 24. 
The planes 6-$ are six in number at each 
extremity, and are so situated that they 
give a spiral aspect to the crystal. If 
these planes were cnly three in number 
at each extremity, the alternate three of 
the six, the form would be tetartohedral 
to the double six-sided pyramid ; that is, 
there would be one fourth the number of 
planes that exist in the double twelve- 
sided pyramid, or 6 planes instead of 24. 
Such cases of hemihedrism and tetarto- 
hedrism are common in crystals of quartz, WV , 
and when existing, the crystals are said 
to be plagihedral, from the Greek for oblique and face. In 
some crystals the spiral turns ¢o the right and in others ¢o 
the left, and the two kinds are distinguished as right-handed 
and left-handed. ‘There are also tetartohedral forms in 
which one whole pyramid of a scalenohedron, or of a rhom- 
bohedron, is wanting. For example, in crystals of tourma- 
line rhombohedral planes, and sometimes scalenohedral, 
may occur at one extremity of the prism and be absent 
from the other. This dissimilarity in the two extremities 
of a crystal of tourmaline is connected with pyro-electric 
polarity in the mineral. Three-sided prisms, hemihedral 
to the hexagonal prism, are common in some rhombohedral 
species, as tourmaline. 

4, Cleavage.—Cleavage usually takes place parallel to 
the faces of a rhombohedron, as in calcite, 
corundum. Not unfrequently the rhombohe- 
dral cleavage is wanting, and there is highly ff 
perfect cleavage parallel to the basal plane, as f7<eq/77 
in graphite, brucite. < 

5. Irregularities of Crystals—Distortions 7 
occur of the same nature with those under the other 


24. 








56 CRYSTALLOGRAPHY. 


systems. Some examples are given under quartz. Some 
rhombohedral species, as dolomite, have the opposite faces 
convex or concave, as in Fig. 25. 

Occasional curved crystals occur, as in Fig. 26, repre- 
senting crystals of quartz, and Fig. 27 of a crystal of chlo- 


26. 27. 





TANNA WR! 
INR 


QUARTZ. CHLORITE. 





rite. The feathery crystallizations on windows, called frost, 
are examples of curved forms under this system. 


VII. DISTINGUISHING CHARACTERS OF THE SEVERAL 
SYSTEMS OF CRYSTALLIZATION. 


1. IsomETRIC SystEM.—(1) There may be symmetrical 
groups of 4 and 8 similar planes about the extremities of 
each cubic axis; and of 3 or 6 similar planes about the ex- 
tremities of each octahedral axis. (2) Simple holohedral 
forms may consist of 6 (cube), 8 (octahedron), 12 (dodeca- 
hedron), 24 (trapezohedron, trigonal trisoctahedron, and 
tetrahexahedron), and 48 (hexoctahedron) planes. 

2. TETRAGONAL SYSTEM.—(1) Symmetrical groups of 
4 and 8 similar planes occur about the extremities of the 
vertical axis only. (2) Prisms occur parallel only to the 
vertical axis; and these prisms are either square or eight- 
sided. (3) The simple holohedral forms may consist of 2 
planes (the bases), of 4 planes (square prisms), of 8 planes 
(eight-sided prisms and square octahedrons), of 16 planes 
(double eight-sided pyramids). 

3. ORTHORHOMBIC SYSTEM.—(1) Symmetrical groups of 
4 similar planes may occur about the extremities of either 
axis, but those of one axis may be referred equally to the 
others. (2) The prisms are rhombic prisms only, and 
these may occur parallel to either of the axes, the horizon- 


TWIN, OR COMPOUND, CRYSTALS. 57 


tal as well as the vertical. (3) Simple holohedral forms 
may consist of 2 planes (the bases, and each pair of dia- 
metral planes), of 4 planes (rhombic prisms in the three 
axial directions), and of 8 planes (the rhombic octahedrons). 
(4) The forms may be divided into equal halves, symmet- 
rical in planes, along each of the diametral sections. 

4, Monociinic System.—(1) No symmetrical groups of 
similar planes ever occur around the extremities of either 
axis. (2) The prisms are rhombic prisms, and these can 
occur parallel only to the vertical axis and the clinodiagonal. 
(3) The planes occurring in vertical sections above and 
below the basal section, either in front or behind, are all 
unlike in inclination to that section, excepting the pris- 
matic planes in the orthodiagonal zone. (4) Simple forms 
consist of 2 planes (the bases, the diametral planes, and 
hemiorthodomes), of 4 planes (rhombic prisms in two direc- 
tions and hemioctahedrons). (4) The forms may be di- 
vided into equal and similar halves only along the clinodi- 
agonal section. No interfacial angle of 90° occurs except 
between the planes of the clinodiagonal zone and the 
clinopinacoid. 

5. TRICLINIC System.—In triclinic crystals there are no 
groups of similar planes which include more than 2 planes, 
and hence the simple forms consist of 2 planes only. The 
forms are not divisible into halves having symmetrical 
planes. ‘There are no interfacial angles of 90°. 

6. HEXAGONAL SYSTEM.—Symmetrical groups of 3, 6, 
and 12 similar planes may occur about the extremities of 
the vertical axis. (2) Prisms occur parallel to the vertical 
axis, and are either six- or twelve-sided (8 in a hemihedral 
form) and equilateral. (83) Simple holohedral forms may 
consist of 2 planes (the basal), of 6 planes (hexagonal prism), 
of 12 planes (twelve-sided prisms and double six-sided pyra- 
mids), of 24 planes (double twelve-sided pyramids). Simple 
rhombohedral forms may consist of 2 planes (the basal), of 6 
planes (rhombohedrons), and of 12 planes (scalenohedrons). 

The distinguishing optical characters are mentioned 
beyond. 


2. TWIN, 0g COMPOUND, CRYSTALS. 


Compound crystals consist of two or more single crystals, 
united usually parallel to an axial or diagonal section. A few 


58 CRYSTALLOGRAPHY. 


are represented in the following figures. Fig. 1 represents 
a crystal of snow of not unfrequent occurrence. As is evi- 
dent to the eye, it consists either of six crystals meeting in 
a point, or of three crystals crossing one another; and, be- 
sides, there are numerous minute crystals regularly arranged 
along the rays. Fig. 2 represents a cross (cruciform) crys- 





tal of staurolite, which is similarly compound, but made. up 
of two intersecting crystals. Fig. 3 is a compound crystal 
of gypsum, and Fig. 4 one of spinel. ‘These will be under- 
stood from the following figures. 

Fig. 5 is a simple crystal of gypsum; if it be bisected 

along ad, and the right half be 

o. 6. inverted and applied to the other, 

: it will form Fig. 3, which is there- 

fore a twin crystal in which one 

half has a reverse position from 

the other. Fig. 6 is a simple oc- 

tahedron ; if it be bisected along 

the plane adcde, and the upper 

half, after being revolved half 

| way round, be then united to the 

lower, it will have the form of Fig. 4. Both of these, 

therefore, are similar twins, in which one of the two com- 
ponent parts is reversed in position. 

Crystals like Figs. 3 and 4 have proceeded from a com- 
pound nucleus in which one of the two molecules was re- 
versed ; and those like Fig. 1, from a nucleus of three (or 
six) molecules. Compound crystals of the kinds above de- 
scribed thus differ from simple crystals in having been 
formed from a nucleus of two or more united molecules, 
instead of from a simple nucleus. 

Compound crystals are generally distinguished by their 
re-entering angles, and often also by the meeting of striz 





1g 


TWIN, OR COMPOUND, CRYSTALS. 59 


at an angle along a line on a surface of a crystal, the line 
indicating the plane of junction of the two crystals. 

Compound crystals are called ¢wolings, trillings, fourlings, 
according as they consist of two, three, or four united crys- 
tals. Fig. 1 represents a trilling, and 2, 3, and 4, twolings. 
In 3 and 4 the combined crystals are simply in contact 
along the plane of junction; in 2 they cross one another ; 
the former are called contact-twins and the latter penetra- 
tion-twins. 

Besides the above, there are also geniculated crystals, as 
in the annexed figure of a crystal of rutile. The bending 
has here taken place at equal distances from the centre of 
the crystal, and it must therefore have been subsequent in 
time to the commencement of the crystal. 
The prism began from a simple molecule ; 
but after attaining a certain length an ab- 
rupt change of direction took place. The 
angle of geniculation is constant in the 
same mineral species, for the same reason 
that the interfacial angles of planes are 
fixed ; and it is such that a cross-section 
directly through the geniculation is parallel to the position 
of a common secondary plane. In the figure given, the 
plane of geniculation is parallel to one of the terminal 
edges. In rutile the geniculated crystals sometimes repeat 
the bendings at each end until the extremities meet to form 
a wheel-like twin. 

In some species, as albite, the reversion of position on 
which this kind of twin depends, takes place at so short in- 

tervals that the crystal consists of 

8. parallel plates, each plate often 

less than a twentieth of an inch 

in thickness. <A section of such 

a crystal, made transverse to the 

plate, is given in Fig. 8; without 

the twinning the section would 

have been as in Fig. 9.- The 

plates, as the figure shows, make 

with one another at their edges a 

re-entering angle (in albite an 

angle of 172° 48’), and hence a 

plane of the albite crystal at right angles to the twinning 
direction, is covered with a series of ridges and depressions 





60 CRYLTALLOGRAPHY. 


which are so minute as to be only fine striations, sometimes 
requiring a magnifying power to distinguish. Such stria- 
tions in albite are therefore an indication of the compound 
structure. 

This kind of twinning is sometimes called polysynthetic 
twinning. It occurs in all the triclinic feldspars, and is a 
means of distinguishing them from orthoclase. Similar 
twinning occurs also in calcite, and some other species. 

In some twin crystals the two component parts of the 
crystal are not united by an even 
plane, but run into one another with 
great irregularity. Cases of this kind 
occur in the species quartz in twins 
made up of the forms # and —£ (or 
—1). In Fig. 10 the shaded parts of 
the pyramidal planes are of the form 
=| —1, and the non-shaded parts of R. 
==| Hach of the faces is made up partly of 

|} R and partly of —1. The limits of 
the two are easily seen on holding the 
crystal up to the light, since the —1 
portion is less well polished than the 
other. In this crystal, as in other 
crystals of quartz, the striations of 
planes 7 are owing to oscillations between pyramidal and 
prismatic planes while the formation of the latter was in 
progress. 

The compound or twinned condition, while often origi- 
nating in a compound nucleus, and in external molecular 
influences, may also be produced in many species by pres- 
sure or a blow. 

In this way a simple rhombohedron of calcite may be 
made a true twin crystal, or a polysynthetic twin. The 
grains in a white crystalline limestone or marble—the spe- 
cies calcite or dolomite—are rhombohedral in cleavage, like 
_ the ordinary crystals of these minerals; but the cleavage 
surfaces are usually striated parallel to the longer diameter 
of the rhombohedral faces, and this striation is due to 
polysynthetic twinning. It may be always a result of pres- 
sure at the time of the crystallization of the limestone. 
The striations common in the triclinic feldspars have been 
attributed to the same cause. 




































































PARAMORPHS. PSEUDOMORPHS. 61 


3. PARAMORPHS. PARAMORPHISM. 


Many examples exist in which elements, and compounds 
that have the same composition essentially, differ in crys- 
talline form as well as other physical qualities. These are 
examples of paramorphism. Among the elements, one 
marked example is carbon, which is isometric in the 
diamond, but hexagonal in graphite: of extreme hardness, 
adamantine lustre, and a specific gravity of 3°53 in the 
former; of extreme softness, a metallic lustre, and a spe- 
cific gravity of 2°1 in the latter. Such differences may be 
conceived of as due to differences in molecular condensa- 
tion. The following are examples among compounds: 
Calcium carbonate occurs rhombohedral (and G. = 2°72) in 
calcite, orthorhombic (and G. = 2°93) in aragonite. Silica 
is rhombohedral (the hemihedral section of the hex- 
agonal system) (and G. = 2°65) in quartz; true hexagonal 

= 2°29) in tridymite; and uncrystallizable in opal 
(G.=2°17). Titanium dioxide hasan orthorhombic form 
in brookite, one tetragonal form in rutile, and another 
tetragonal in octahedrite. In the hornblende group, 
hornblende and pyroxene are alike in composition and in 
monoclinic crystallization; but the former has a cleavage 
angle of 124° 30’, and the latter of 87° 5’. In addition, 
other species of the group having these two cleavage an- 
gles, as anthophyllite and enstatite, are orthorhombic in 
crystallization. 

In general one of the forms is less stable under the or- 
dinary temperature or conditions than the other, because 
it requires for formation a higher temperature or some 
other unusual condition. Thus pyroxene is less stable than 
hornblende; aragonite than calcite, brookite than rutile. 


4, PSHUDOMORPHS, PSEUDOMORPHISM. 


The crystalline forms under which a species occurs are 
sometimes those of another species. Quartz often has the 
crystalline form of calcite, owing to a substitution of silica 
for the calcium carbonate of the calcite crystal. Serpen- 
tine has often the form of chrysolite, chondrodite, or some 
other magnesium mineral, owing to a change in these other 
magnesium silicates into the hydrous magnesium silicate 


62 CRYSTALLOGRAPHY. 


called serpentine. Such false forms are called pseudo- 
morphs, from the Greek pseudos, false, and morphe, form. 
The same process that turned the calcite into quartz has 
converted wood, shells, and corals into quartz; in other 
words, made silicified wood, shells, and corals. 

The different kinds of pseudomorphism are the following: 

1. By substitution: as in the substitution of silica 
(quartz) for the calcite. 

2. By chemical alteration: as in the change to serpen- 
tine above explained; or the change of iron carbonate (sid- 
erite) to the hydrous iron oxide (limonite). _ 

3. By impression: as in deposition in a cavity once occu- 
pied by a crystal; or against the exterior of a crystal. 

4, By paramorphism: as when pyroxene becomes 
changed to hornblende, or aragonite to calcite. In this al- 
teration of pyroxene, as fast as the outer part becomes 
changed, it has cleavage parallel to the hornblende 
prism (JA J = 124° 30"), instead of that of pyroxene (87° 
5’), as in the accompanying figure, 
which in its central part repre- 
sents a transverse section of a 
; crystal, the centre pyroxene, the 
outer part hornblende, and in the 
upper corner a longitudinal section 
of a similarly altered pyroxene. | 
The cleavage-lines are often an 
indication of its progress. Such 
hornblende has been called 27 alite, 
because first observed (by H. Rose) 
in arock of the Urals; but it is essentially. like ordinary 
hornblende. In the figure the black spots represent grains 
of magnetite. In many cases no change in composition 
attends the change; but in others there are some replace- 
ments by which the elimination of unessential ingredients 
takes place. Iron is apt to be this removed ingredient, as 
it is in many of the methods of chemical alteration; and, 
consequently, while it remains in the crystal it takes an 
independent form, and usually that of minute grains or 
crystals of magnetite, or hematite, or menaccanite. 





CRYSTALLINE AGGREGATES, 63 


5. CRYSTALLINE AGGREGATES. 


The crystalline aggregates here included are the simple, 
not the mixed; that is, they are those consisting of crys- 
talline individuals of a single species. 

The crystalline individuals may be (1) distinct crystals; 
(2) fibres or columns; (3) scales or lamellae; or (4) grains, 
either cleavable or not so. 

1. Consisting of distinct erystals.—The distinct crystal 
may be either long or short prismatic, stout or slender to 
acicular (needle-like), and capillary (hair-like); or they 
may have any other forms of crystals. They may be ag- 
gregated (a) in lines; (4) promiscuously with open spaces; 
(c) over broad surfaces; (d) about centres. The various 
kinds of aggregates thus made are: 

a. Filiform.—Thread-like lines of crystals, the crystals 
often not well defined. 

b. Dendritic.—Arborescent slender spreading branches, 
somewhat plant-like, made up of more or less distinct crys- 
tals, as in the frost on windows, and in arborescent forms 
of native copper, silver, gold, etc. 

Fig. 11 represents, much magnified, an arborescent form 
of magnetite occurring in mica at Pennsbury, in Pennsyl- 
vania. Arborescent delineations over surfaces of rock are 
usually called dendrites. 'They have been formed by crys- 
tallization from a solution 11. 
of mineral matter which 
has entered by some crack 
and spread between the 
layers of the rock. They 
are often black, and consist 
of oxide of manganese; 
others, of a brownish color, 
are made of _ limonite; 
others, of a reddish black , 
or black color, of hematite. 
Moss-like forms also occur, 
as in moss agate. 

c. Reticulated.—Slender EROS 
prismatic crystals promis- 
cuously crossing, with open spacings. 

d. Divergent.—Free crystals radiating from a central 
point. 





64 CRYSTALLOGRAPHY. 


e. Drusy.—A surface is drusy when covered with im- 
planted crystals of small size. 

2. Consisting of columnar individuals. 

a. Oolumnar, when the columnar individuals are stout. 

6. Fibrous, when they are slender. 

c. Parallel fibres, when the fibres are parallel. 

d. Radiated, when the columns or fibres radiate from 
centres. 

e. Stellated, when the radiations from a centre are equal 
around, so as to make star-like or circularly-radiated groups. 

f. Globular, when the radiated individuals make globu- 
lar or hemispherical forms, as in wavellite. 

g. Botryoidal, when the globular forms are in groups, a 
little like a bunch of grapes. ‘The word is from the Greek 
for a bunch of grapes. 

h. Mammillary, having a surface made up of low and 
broad prominences. ‘The term is from the Latin mammii- 
la, a little teat. a: 

1. Coralloidal, when in open-spaced groupings of slender 
stems, looking like a delicate coral. A result of successive 
additions at the extremity of a prominence, lengthening it 
into cylinders, the stems generally having a faintly radi- 
ated structure. 

Specimens of all these varieties of columnar structure, 
excepting the last, often have a druwsy surface, the fibres or 
columns ending in projecting crystals. 

3. Consisting of scales or lamelle. 

a. Plumose, having a divergent arrangement of scales, as 
seen on a surface of fracture; e.g., plumose mica. 

b. Lamellar, tabular, consisting of flat lamellar crystal- 
line individuals, superimposed and adhering. 

c. Micaceous, having a thin fissile character, due to the 
aggregation of scales of a mineral which, like mica, has emi- 
inent cleavage. 

d. Septate, consisting of openly-spaced intersecting tabu- 
lar individuals; also divided into polygonal portions by 
reticulating veins or plates. <A septariwm is a concretion, 
usually flattened spheroidal in shape, the solid interior of 
which is intersected by partitions; these partitions are the 
fillings of cracks in the interior that were due to contraction 
on drying. Such septate concretions, especially when worn 
off at surface, often have the appearance of a turtle’s back, 
and are sometimes taken for petrified turtles, 


CRYSTALLINE AGGREGATES. 65 


4, Consisting of grains. Granular structure.—A mas- 
Sive mineral may be coarsely granular or finely granular, 
as in varieties of marble, granular quartz, etc. It is termed 
saccharoidal when evenly granular, like loaf-sugar. It may 
also be cryptocrystalline, that is, having no distinct grains 
that can be detected by the unaided eye, as in flint. The 
term cryptocrystalline is from the Greek for concealed crys- 
talline. Aphanitic, from the Greek for invisible, has the 
same signification. The term ceroid is applied when this 
texture is connected with a waxy lustre, as in some common 
opal. 

Under this section occur also globular, botryoidal, and 
mammillary forms, as a result of concretionary action in 
which no distinct columnar interior structure is produced. 
They are called pisolitic when in masses consisting of grains 
as large as peas (from the Latin piswm, a pea), and odlitic 
when the grains are not larger than the roe of a fish, from 
the Greek for egg. 

5. Lorms depending on mode of deposition.—Besides the 
above, there are the following varieties which have come 
from mode of deposition: 

a. Stalactitic, having the form of a cylinder, or cone, 
hanging from the roofs of cavities or caves. The term 
stalactite is usually restricted to the cylinders of calcium 
carbonate hanging from the roofs of caverns; but other 
minerals are said to have a stalactitic form when resembling 
these in their general shape and origin. Chalcedony and 
limonite are often stalactitic. Interiorly the structure may 
be either granular, radiately fibrous, or concentric. 

The waters percolating through the roofs of limestone caverns hold 
some limestone in solution; and the deposit which each successive drop 
of water makes, lengthens out the cylinder; and not unfrequently they 
become yards in length, or reach from roof to floor. The stalactites 
are sometimes hollow cylinders when small, because the drops, which 
follow one another very slowly, evaporate chiefly at the outer margin 
of each, the first one thus making a ring, and the following lengthen- 
_ ing the ring into the cylinder. The solution is strictly a solution of 
calcium bicarbonate; as evaporation takes place the excess of carbonic 
acid goes off and calcium carbonate is deposited. 

b. Concentric.—When consisting of lamelle, lapping one 
over another around a centre, a result of successive concre- 
tionary aggregations, as in many concretionary forms, most 
pisolite, part of odlite, some stalactites, etc. 

c. Stratified, consisting of layers, as a result of deposi- 
tion : ¢.g., some travertine, or tufa. 


~ 
La 


» 
a 


66 PHYSICAL PROPERTIES OF MINERALS. 


d. Banded, straticulate ; color-stratified. Like stratified 
in origin, but the layers thin and usually indicated only 
by variations in color or texture; the banding is shown in 
a transverse section: e.g., agate, much stalagmite, riband 
jasper, some limestone; it becomes lamellar or slaty when 
the little layers are separable. 

e. Geodes.—When a cavity has been lined by the deposi- 
tion of mineral matter, but not wholly filled, the enclosing 
mineral is called a geode. The mineral is often banded, 
owing to the successive depositions of the material, and 
frequently has its inner surface set with crystals. Agates 
are often slices or fragments of geodes. 

6. Hracture.-—Kinds of fracture in these crystalline ag- 
gregates depend on the size and form of the particles, their 
cohesion, and to some extent their having cleavage or not. 

Among granular varieties, the influence of cleavage is in 
all cases very small, and in the finest almost or quite noth- 
ing. The term hackly is used for the surface of fracture 
of a metal, when the grains are coarse, hard, and cleavable, 
so as to be sharp and jagged to the touch; even, for any 
surface of fracture when it is nearly or quite flat, or not at 
all conchoidal; conchoidal, when the mineral, owing to its 
extremely fine or cryptocrystalline texture, breaks with 
shallow concavities and convexities over the surface, as in 
the case of flint. The word conchoidal is from the Latin 
concha, a shell. These kinds of fracture are not of great 
importance in mineralogy, since they distinguish varicties 
of minerals only, and not species. 


II. PHYSICAL PROPERTIES OF MINERALS. 


THE physical properties referred to in the description 
and determination of minerals are here treated under the 
following heads: (1) Hardness; (2) Tenacity; (3) Specific 
Gravity; (4) Refraction, Polarization; (5) Diaphaneity, 
Color, Lustre; (6) Electricity and Magnetism; (7) Taste 
and Odor. All excepting the last are more or less depend- 
ent on the crystallization, the qualities in each case being 
alike in crystals in the direction of like or equal axes, and 
usually unlike in the directions of unlike or unequal axes. 


HARDNESS—TENACITY. 67 


1. HARDNESS. 


The comparative hardness of minerals is easily ascer- 
tained, and should be the first character attended to by the 
student In examining a specimen. It is only necessary to 
draw a file across the specimen, or to make trials of scratch- 
ing one with another. As standards of comparison the 
following minerals have been selected, increasing gradually 
in hardness from falc, which is very soft and easily cut with 
a knife, to the diamond. ‘This table, called the scale of 
hardness, is as follows: 

1, tale, common foliated variety; 2, rock salt; 3, calcite, 
transparent variety; 4, fluorite, crystallized variety; 5, 
. apatite, transparent crystal; 6, orthoclase, cleavable variety; 

7, quartz, transparent variety; 8, topaz, transparent crys- 
tal; 9, sapphire, cleavable variety; 10, diamond. 

If, on drawing a file across a mineral, it is impressed as 
easily as fluori/e, the hardness is said to be 4; if as easily as 
orthoclase, the hardness is said to be 6; if more easily than 
orthoclase, but with more difficulty than apatite, its hard- 
ness is described as 54 or 5°5. 

The file should be run across the mineral three or four 
times, and care should be taken to make the trial on angles 
equally blunt, and on parts of the specimen not altered by 
exposure. ‘Trials should also be made by scratching the 
specimen under examination with the minerals in the above 
scale, since sometimes, owing to a loose aggregation of par- 
ticles, the file wears down the specimen rapidly, although 
the particles are very hard. 

In crystals the hardness is sometimes appreciably different 
in degree in the direction of different axes. In crystals of 
mica the hardness is less on the basal plane of the prism, 
that is, on the cleavage surface, than it is on the sides of 
the prism. On the contrary, the termination of a crystal 
‘of cyanite is harder than the lateral planes. The degree 
of hardness in different directions may be obtained with 
ereat accuracy by means of an instrument called a sclero- 
meter. 


2. TENACITY. 


The following rather indefinite terms are used with 
reference to the qualities of tenacity, malleability, and flexi- 
bility in minerals: 


63 PHYSICAL PROPERTIES OF MINERALS. 


1. Brittle.-—When a mineral breaks easily, or when parts 
of the mineral separate in powder on attempting to cut it. 

2. Malleable.—When slices may be cut off, and these 
slices will flatten out under the hammer, as in native gold, 
silver, copper. 

3. Sectile.—When thin slices may be cut off with aknife. 
All malleable minerals are sectile. Argentite and cerargy- 
rite are examples of sectile ores of silver. The former cuts 
nearly like lead, and the latter nearly like wax, which it re- 
sembles. Minerals are imperfectly sectile when the pieces 
cut off pulverize easily under a hammer, or barely hold 
together, as selenite. 

4. Hlexible-—When the mineral will bend, and remain 
bent after the bending force is removed. Hxample, tale. 

5. Hlastic.—When, after being bent, it will spring back 
to its original position. Hxample, mica. 

A liquid is said to be viscows when on pouring it the 
drops lengthen and appear ropy. 


3. SPECIFIC GRAVITY. 


The specific gravity of a mineral (called also its density) 
is its weight compared with that of some substance taken 
as a standard. For solids and liquids distilled water, at 
60° F., is the standard ordinarily used; and if a mineral 
weighs twice as much as water, its specific gravity is 2; if 
three times it is 3. It is then necessary to compare the 
weight of the mineral with the weight of an equal bulk of 
water. ‘The process is as follows: 

First weigh a fragment of the mineral in the ordinary 
way, with a delicate balance; next suspend the mineral by 
a hair, or fibre of silk, or a fine platinum wire, to one of 
the scales, immerse it, thus suspended, in a glass of distilled 
water (keeping the scales clear of the water) and weigh it 
again; subtract the second weight from the first, to ascer- 
tain the loss by immersion, and divide the first by the dif- 
ference obtained; the result is the specific gravity. ‘The 
loss by immersion is equal to the weight of an equal volume 
of water. The trial should be made on a small fragment; 
two to five grains are best. The specimen should be free 
from impurities and from pores or air-bubbles. For exact 
results the temperature of the water should be noted, and 
an allowance be made for any variation from the height of 


SPECIFIC GRAVITY. 69 


thirty inches in the barometer. The observation is usually 
made with the water at a temperature of 60° F.; 39°°5 F., 
the temperature of the maximum density of water, is pref- 
erable. 

The accompanying figure represents the spiral balance 
of Jolly, by which the density is meas- 
ured by the torsion of a spiral brass 
wire. On the side of the upright (A) 
which faces the spiral wire, there is a 
graduated mirror, and the readings 
which give the weight of the mineral in 
and out of water are made by means of 
an index (at m) connected with the 
spiral wire; and its exact height, with 
reference to the graduation, is obtained 
by noting the coincidence between it 
and its image as reflected by the gradu- 
ated mirror. c and d are the pans in 
which the piece of mineral is placed, 
first in c, the one out of the water, and 
then in d, that in the water. 

In using the spiral balance the spiral 
spring is put at any desired height by 
means of the sliding-rod C. The stand 
B is raised so that the lower pan, d, 
shall be in the water, while the other, ec, 
is above it. ‘The position of the index, 
or signal, m, is then noted, by sighting 
across it and observing that the index 
and the image of it in the mirror are in the same horizontal 
line; let s stand for it. Next put the fragment of the 
mineral in c, and drop the stand B until the lower pan 
hangs free in the water, and note the position of m, which we 
may represent by ¢; ¢—s represents the weight in the air. 
Now place the fragment in the lower pan, and after adjust- 
ing again the stand £&, the position of m is noted as before; 
eall it w. Then ¢—w=loss of weight in water. From 
these values the specific gravity is at once obtained. 

Another process, and one available for porous as well as 
compact minerals, is performed with a light glass bottle, 
capable of holding exactly a thousand grains (or any known 
weight) of distilled water. ‘The specimen should be re- 
duced to a coarse powder. Pour out a few drops of water 








70 PHYSICAL PROPERTIES OF MINERALS. 


from the bottle and weigh it; then add the powdered min- 
eral till the water is again to the brim, and reweigh it; the 
difference in the two weights, divided by the loss of water 
poured out, is the specific gravity sought. ‘The weight of 
the glass bottle itself is here supposed to be balanced by an 
equivalent weight in the other scale. 

Another method consists in the use of a solution of a salt 
of high specific gravity. The potassium-mercury todide is 
one salt so used, and another is the cadmium boro-tungs/ate. 
The maximum density of a solution of the former is 3°23 of 
the latter, 3°6. By carefully adding water, the solution is 
reduced in density to that of the mineral, or that in which 
the mineral in coarse grains will just float; and this den- 
sity is then determined by weighing a given amount of 
the solution. ‘The process is used also for the separation of 
mixed minerals of unequal density. Details of the processes 
will be found in larger works. 


4. REFRACTION AND POLARIZATION. 


Light is refracted when it passes from a rarer medium 
through a denser, as from air through water, or the re- 
verse. It is polarized, or has its vibrations reduced to v- 
brations in a plane, when it passes through a crystal of un- 
equal crystallographic axes, or a fragment of such a crystal. 

Amorphous substances (or those totally devoid of traces of 
crystallization), like glass and opal, and crystallized sub- 
stances of the vsometric system, have single or simple refrac- 
tion; while substances crystallized under either of the other 
systems of crystallization have double refraction. 

SIMPLE REFRACTION.—The index of ordinary refraction 
is obtained by dividing the sine of the angle of incidence of 
the ray of light by the sine of its 
angle of refraction. Thus if a ray 
of light (ad, Fig. 1) strike the sur- 
face (JZ) of the denser material at 
an angle of 60° from the perpendic- 
ular (the angle dag), and then passes 
through it at an angle of 40° from 
the perpendicular (angle cab), the 
sine of 60° (ad), divided by the sine 
of 40° (ae), will be the index of re- 
fraction. 

The index of refraction of air being taken as the unit, 





REFRACTION AND POLARIZATION, vas 


that of water, as experiment has ascertained, is 1°335; of 
fluorite, 1°434; of rock-salt, 1°557; of spinel, 1°764 5 of 
garnet, 1°815; of blende, 2°260; of diamond, 2-439. 

Isometric and amorphous substances are said to be 7so/ro- 
pic, because in them the velocity of light and all light-phe- 
nomena are alike in all directions. 

DovuBLE REFRACTION. POLARIZATION.—Double refrac- 
tion is illustrated in the annexed figure representing a trans- 
parent rhombohedron of calcite, 
with the ray, ad, divided, as it passes 
through the crystal, into two rays ac 
and ac’, When such a crystal is 
placed over a dot the dot appears 
double, owing to the double refrac- 
tion, Hach of these rays is a polar- 
ized ray. 

Such crystals are optically either 
uniaxial or biaxial. 

A. Uniazial.—Uniaxial substances are those of the tetrag- 
onal and hexagonal systems; and the vertical axis, about 
which the parts are arranged symmetrically, is the optic 
axis. In the direction of this axis refraction is simple, but 
in all other directions dowble ; and the divergence is greatest 
in a direction at right angles to the vertical or optic axis. 

One of the rays has its vibrations ¢ransverse to the axis: 
it is called the ordinary ray, because it obeys the laws of or- 
dinary refraction above explained. 'The other, the extraor- 
dinary ray, has its vibrations in the direction of the axis, 
and obeys a different law, because the elasticity of the light- 
ether in this direction is greater or less than in the trans- 
verse. If the index of refraction of the extraordinary ray 
(€) is greater than that of the ordinary (@), the crystal is 
said to be positive ; if less, it is negative. Calcite is an 
example of a negative crystal, ac in Fig. 2 being the extra- 
ordinary ray ; and quartz is an example of a positive. 

Plates of tourmaline made by vertical sections of a 
transparent crystal transmit the extraordinary ray, while 
the ordinary ray is absorbed. Hence such plates are con- 
venient for optical investigations. A simple polariscope 
made of two tourmaline plates has the form in Fig. 3. 
The effects are the same whichever tourmaline plate is 
brought to the eye. The plate away from the eye, or that 
receiving the light for transmission, is called the polarizer, 





T2 PHYSICAL PROPERTIES OF MINERALS. 


and the other the analyzer. Light passes freely through 
the two plates as long as they have the position they had in 
the crystal, that is, have the vertical axes—the planes of 
vibration—of the two parallel. But if the axes are crossed, 
by revolving one plate 90°, no light passes. Ina revolu- 





tion, light and dark fields alternate every 90°. Crystalline 
minerals are examined by placing sections of them between 
the tourmalines. : 

Calcite, owing to the wide divergence of its refracted 
rays, is commonly used for polarizing apparatus. In a 

4. ‘‘nicol prism” of calcite (Fig. 4) the extraor- 
dinary ray (ac’) passes through the prism, while 
the other (ac) is got rid of by reflection from 
the surface of Canada balsam (mn) along 
which the two pieces of calcite in the prism are 
joined. 

In a polariscope the two nicols are mounted 
in tubes, one of which, if the instrument is a 
vertical one, is placed above, and the other 
below, a stage arranged for receiving the object 
for examination. One or both of the nicols, 
and also the stage, admits of revolution, in 
order to place the planes of vibration of the 
nicols in different positions as to one another 
and as tothe specimen centered on the stage; and graduated 
scales indicate the angle of revolution in nicol and stage. 
Lenses for magnifying the object are added; and also 
others, making what is called the condenser, which is placed 
between the polarizer and the stage. : 

In the ordinary polariscope, only very low magnifying- 
powers are used without an ocular, and consequently the 
field is large so as to be convenient for observations on the 
light-phenomena. By inserting the condenser the trans- 





REFRACTION AND POLARIZATION. 


Sitter me 
Sr oS EE & 





x 
ls 
im 
D rz re RE RTEEETIREESS AREER ERAS DOT OEE 
Sse Ses SS 
Soa 





IK 


- i 2 


\ a 
= 
=| 
2 
= 


© 
ll m >» 


a He 














6) 


74 PHYSICAL PROPERTIES OF MINERALS. 


mission of the polarized light in parallel rays is changed to 
transmission in convergent rays; and the light-phenomena 
are changed. 

In the polarization-microscope (a figure of which is here 
introduced) higher powers are used, and also an ocular (eye- 
piece with lenses). The nicols are at ss (analyzer) and rr 
(polarizer); the supporting tube of the analyzer revolves, 
and rests on a graduated circle ff, with a mark on the 
edge which is to be set at 0° to put the vibration-planes of 
the two nicols in a crossed position, and at 90° to make them 
parallel. 'The tube of the microscope moves up and down, 
by the hand, within the outer case pp ; and a fine adjustment 
is obtained with the screw g, the surface of which is gradu- 
ated. In the figure the condenser 7'7' is in place, as when 
required for observations with converging rays (which are 
made with the ocularremoved). ‘The stage revolves and has 
a lateral movement by screws to aid in centering the object ; 
and to give further aid, the tube has a slight movment by 
the screw nn. ¢¢ isan opening for inserting a plate of quartz 
(ZZ,) for determining the precise position when an axis of 
elasticity of the object on the stage coincides with a vibra- 
tion-plane of a nicol, and for other purposes. 

On revolving one of the nicols, the change from the 
transmission of light to its non-transmission by the analyzer, 
or the ‘‘ extinction of the ray,” takes place with every 90° 
of revolution, as with the tourmaline polariscope; and alike 
for parallel and converging light. 

If a plate of a uniaxial crystal cut at right angles to the 
vertical or optic axis is on the stage centered in the field of 
view, and the nicols are crossed and parallel light is used, 

the field remains dark 

6. ce through the complete 
revolution of the stage, 
as in the case of isometric 
and isomorphous  sub- 
stances; but if converg- 
ing light is used in the 
Be ariscope, asymmetrical 
lack cross and concentric 
spectrum-circles are seen 
when the nicolsare crossed 
(Fig. 6), and a light-cross with the colors reversed (Fig. 7) 
when they are parallel. The number of spectrum-rings 














REFRACTION AND POLARIZATION. 75 


within the field under a given convergence and magnifying- 
power depends on the refraction and the thickness of the 
plate under examination. The plate may be so thin that 
it will have but one color, or none. ‘The tourmaline- 
polariscope affords the same cross and circles or ‘‘ interfer- 
ence-figures,” because the eye is brought so closely to the 
analyzer in making observations that the light is really 
converging light. 

When the ordinary thin sections mounted on glass are 
examined in the polarization-microscope, it is commonly the 
case, owing to the thinness of the sections, that few if any 
of the colored rings around the centre of the black cross 
are in sight. If the sections for examination, instead of 
being cut parallel to the base of the crystal, or at right 
angles to the optic axis, are cut a little oblique to it but at 
right angles still to a vertical axial section, the cross will 
be symmetrical, but its centre out of the centre of the field; 
and if cut much oblique to it, its centre may be wholly out 
of the field, and only one straight black band be visible. 

Circular polarization characterizes quartz. The light- 
vibrations instead of being in a single plane rotate either 
to the right or left, according as the crystal is right-handed 
or left-handed (p. 55). Consequently, a plate cut at right 
angles to the optic or vertical axis has a colored centre to 
the series of spectrum-circles in all positions of the ana- 
lyzer; moreover, on revolving the analyzer the color of the 
centre changes from blue to yellow and red in right-handed 
crystals if the revolution is to the right, and in /e/¢-handed 
when the revolution is in the opposite direction. 

B. Biaxial.—1. In orthorhombic, monoclinic, and triclinic 
crystals the three crystallographic axes are unequal, and 
there is unequal elasticity optically in three directions at 
right angles with one another: a maximum axis (a), a mean 
(b),and a minimum (c). The elasticity in these directions 
is inversely as the refraction-indices for the same direc- 
tions. 

There are fwo directions in which there is no double re- 
fraction, and these are the directions of the two optic azes. 
The two are situated in a plane passing through the axes of 
maximum and minimum elasticity (a and c), and coincide 
with lines in this plane along which the elasticity equals 
that of the mean axis. A line bisecting the acute angle of 
intersection of the two optic axes is called the acute bisec- 


%6 PHYSICAL PROPERTIES OF MINERALS. 


triz, and that for the obtuse angle of intersection, the 
obtuse bisectria. 

Sections of such crystals cut at right angles to a bisectrix 
(but best the acute bisectrix, for the angle bisected by the 

3 9 obtuse is too divergent 
; for viewing well the 
phenomena) show in 
converging polarized 
light, when the plate 
under examination has 
the line joining the 
axes coincident with 
the vibration-plane of 
either nicol-prism, a 
black band or an wn- 
symmetrical black 
cross, similar to that in Fig. 8; if a revolution of 45° is 
made, the form changes to that in Fig. 9. But the plates 
under investigation may be so thin or the axis so divergent 
that the axial centres are not in the field of view. 

2. Inthe Orthorhombic system the three axes of elasticity 
coincide in direction with the crystallographic axes. ‘The 
plane of the two optic axes coincides with one of the three 
axial sections: which of the three is to be determined by 
observations on sections cut parallel to each. 

In observations made with parallel light on sections cut 
parallel to the axial planes, extinction of the light takes 
place whenever the cross-wires in the polarization-micro- 
scope are parallel with the axes of elasticity (or the crystal- 
lographic axes) in the section. The extinction, under the 
orthorhombic system, is hence said to be parallel extinction. 

3. In monoclinic crystals (which have but one plane of 
symmetry—the clinodiagonal, and one axis—the ortho- 
diagonal, at right angles to the plane of the other two) one 
of the axes of elasticity coincides in direction with the or- 
thodiagonal, and the other two (at right angles with it) lie 
in the plane of symmetry. Hither of the three may be that 
of maximum (a), mean (b), or minimum (c) elasticity. 

The plane of the two optic axes may coincide with either 
of the three planes passing through the axes of elasticity 
(one of which planes is that of the clinodiagonal section, 
and the other two are planes at right angles to the clino- 
diagonal section passing through the orthodiagonal and one 














REFRACTION AND POLARIZATION. ae 


other of the axes of elasticity in that section) ; and when 
situated in the clinodiagonal section they are unsymmetrical 
in crystallographic relations, but when in either of the other 
sections they are situated symmetrically either side of the 
clinodiagonal section. 

With reference to observations with parallel light in the 
polarization-microscope, it is to be noted that—since the 
plane of the vertical crystallographic axis and axis of elas- 
ticity makes a right angle with the orthociagonal, like the 
planes of vibration of the crossed nicols, but an oblique 
angle with the clinodiagonal, any section made in the or- 
thodiagonal zone (or at right angles to the clinodiagonal 
section) will have extinction parallel, as in the orthorhombic 
system; but in the case of sections cut in other directions, 
extinction does not take place when either of the planes or 
cleavage lines in the clinodiagonal section is brought to 
parallelism with either vibration-plane of the nicols, and a 
revolution through an angle—different for different species 
and positions—has to be made: the amount of this angle is 
called the extinction-angle as measured from the edge or 
cleavage-line selected for the measurement. [For horn- 
blende and pyroxene, in which the optic axes lie in the 
plane of symmetry, the extinction-angle is measured from 
the cleavage-lines, these being parallel to the vertical axes ; 
it is 15° for hornblende ; 39° for pyroxene; while parallel, 
or 0° (expressed by the symbol || ) for enstatite and hy- 
persthene which are orthorhombic. 

The following figures represent clinodiagonal sections 
of hornblende and pyroxene, having cc as the vertical 
axis, and aa as the clinodiagonal, with the angle of extinc- 
tion marked upon them. AA, LB are the two optic axes, 
and a, c the two axes of elasticity. 

The point of light-extinction is more exactly determin- 
able if a basal section of calcite is placed between the ocular 
and analyzer, and the precise moment observed when the 
distortion of the interference-figures of the calcite ceases. 
But for microscopic investigations a quartz-plate or a Cal- 
deron artificial twin of calcite is used. The quartz-plate is 
inserted above the objective. The nicols being crossed and 
the analyzer revolved until a particular color, say violet, is 
obtained, then, on placing the section on the stage, the 
color will be changed, and will remain different until one of 
the axes of elasticity in the section corresponds with a vibra- 


78 PHYSICAL PROPERTIES OF MINERALS. 


tion-plane in the nicols, when it will be violet again. This 
is the point desired. 
4. In the ¢riclinic system, since there is no plane of 


\ 





HORNBLENDE, PYROXENE. 


symmetry, and the crystallographic axes have no rectangu- 
lar intersections, the positions of the axes of elasticity and 
of the optic axes have to be determined by the optical ex- 
amination of sections cut in different directions, and by the 
angles of extinction measured from different faces of the 
crystal or cleavage-lines. Some hints as to the positions of 
the axes may often be derived from their positions in re- 
lated monoclinic forms of similar chemical compounds; as, 
for the triclinic feldspars from the monoclinic, for rhodonite 
from pyroxene, etc. In the triclinic feldspars the extinc- 
tion-angle is usually measured from the edge between the 
two cleavage-planes, or parallel to the shorter diagonal of O. 
The angle differs for the different kinds, and is the chief 
means of microscopical determination. 

5. Compound crystals, the isometric excepted, are com- 
pound in their optical characters as well as form. ‘The 
component parts have their crystallographic axes in dif- 
erent positions, and hence also their optical axes; and as 
a consequence adjoining spectra have the order of colors 
reversed or otherwise different. When, in the optical ex- 
aminations of thin slices, halves or alternate sectors, or 
alternate bands, differ as to the transmission of light, or as 
to color, there is evidence of a compound structure. In 
- the polysynthetic twins of albite, labradorite, and other 
triclinic feldspars, if the slice cuts across the vertical axis, 


REFRACTION AND POLARIZATION. Td 


parallel bands of light and darkness, or of color, indicate 
the multiplicity in the twinning, as the mineral is revolved 
on the stage. JF ig.12 (from Hawes) shows the number of 
such bands observed in a slice of labradorite (the frac- 
turing is a consequence of a movement that took place in 


13. 


i 
i tint 
ME ee ree r 
5 {fa 


| 
nn 





the rock after the mineral had crystallized). Fig. 13 rep- 
resents the peculiar tessellation in the polysynthetic twin- 
ning of the feldspar, microcline, arising probably from the 
fact that the angle between the two cleavage-planes differs 
but 19’ from 90°. 

For fuller details as to the methods of making optical 
investigations, see the Text-book of Mineralogy, or some 
other large work on the subject. 

6. Anomalies in Polarization.—There are some isometric 
crystals which have the property of polarization. Examples 
occur in crystals of analcite, leu- 
cite, alum, boracite, fluorite, and 
diamond. The facts as to analcite 
were long since described by Sir 
David Brewster, and the annexed 
figure, indicating the arrange- 
ment of the colors or spectra in a 
trapezohedral crystal of this spe- 
cies, is from his paper. In some 
cases also there are variations 
from the isometric angles, which 
seem to point to a tetragonal or 
other form. Leucite has angles ana optical characters 
that have led to its reference to the tetragonal system. 
Analogous conditions exist also in tetragonal and hexagonal 
crystals. The latest view is that all such irregularities are 
due toa molecular strain within the crystals produced. at 
the time of their formation. It has long been known that 

















80 PHYSICAL PROPERTIES OF MINERALS. 


pressure will cause the development of polarizing proper- 
ties in many substances; and these are analogous cases, 
except that the pressure is a strain of molecular origin. 
Optical characters in many of the species under all the 
systems of crystallization vary much, and the above is a 
prominent source of these variations. 

v7. Dichroism, Pleochroism. —Crystals, excepting those of 
the isometric system, when colored, often have different 
colors by transmitted light, and different degrees of trans- 
parency in the directions of unequal axes at right angles 
to one another. In tetragonal and hexagonal crystals 
there may be different colors in the vertical and lateral 
directions; and in those under the other systems there may 
be different colors and transparency in three directions. 
Crystals of tourmaline when transparent or translucent in 
a direction transverse to the prism are opaque in a vertical 
direction, because the ordinary ray is absorbed. Zircon, 
which in a transverse direction is asparagus-green, is pinkish 
brown in a vertical, the light being differently absorbed as 
to its component colors in the two directions. ‘The differ- 
ence in the colors and transparency may be very slight: it 
is so in pyroxene and enstatite, while usually strong in 
hornblende and a hypersthene containing much iron. LEpi- 
dote is an example of a monoclinic mineral with different 
colors in the three axial directions. 

The different colors are best seen by polarized light, and 
this method may be used with very thin sections. On exam- 
ining a plate of zircon cut parallel to a face of the vertical 
square prism, with a single nicol or tourmaline plate, the 
colors appear alternately as the plate or the nicol is revolved. 
The nicol should be first set at 0°, so that its vibration- 
plane coincides with the line 0° to 180° on the stage, and 
then the plate placed on the stage and the stage revolved; 
and the color thus obtained compared with that after a 
revolution of 90°. 


5. DIAPHANEITY, LUSTRE, COLOR. 
1. DIAPHANEITY. 


Diaphaneity is the property which many objects possess 
of transmitting light; or, in other words, of permitting 
more or less light to pass through them. This property is 


DIAPHANEITY, LUSTRE, COLOR. 81 


often called transparency, but transparency is properly one 
of the degrees of diaphaneity. The following terms are 
used to express the different degrees of this property: 

Transparent—when the outlines of objects, viewed 
through the mineral, are distinct. Hxample, glass, crys- 
tals of quartz. 

Subtransparent, or semitransparent—when objects are 
seen but their outlines are indistinct. 

Translucent—when light is transmitted, but objects are 
not seen. Loaf-sugar is a good example; also Carrara 
marble. 

Subtranslucent—when merely the edges transmit light 
faintly. 

When no light is transmitted the mineral is described as 
opaque. 


2. LUSTRE. 


The lustre of minerals depends on the nature of their 
surfaces, which causes more or less light’ to be reflected. 
There are different degrees of intensity of lustre, and also 
different kinds of lustre. 

a. The kinds of lustre are six, and are named from some 
familiar object or class of objects. | 

1. Metallic—the usual lustre of metals. Imperfect me- 
tallic lustre is expressed by the term swbmetallic. 

2. Vitreous—the lustre of broken glass. An imperfect. 
vitreous lustre is termed subvitreows. Both the vitreous 
and subvitreous lustres are common. Quartz possesses the 
former in an eminent degree ; calcite often the latter. This 
kind of lustre may be exhibited by minerals of any color. 

3. Resinous—tustre of the yellowresins. Hxample, some 
opal, zinc blende. 

4, Pearly—like pearl. Example, talc, native magnesia, 
stilbite, etc. When united with. submetallic lustre the 
term metallic-pearly is applied. 

5. Greasy—looking as if smeared with oil. Example, 
elzolite, some quartz. 

6. Silky—tike silk; it is the result of a fibrous structure. 
Example, fibrous calcite, fibrous gypsum, and many 
fibrous minerals, more especially those which in other 
forms have a pearly lustre. 

%. Adamantine—the lustre of the diamond. When sub- 

6 





82 PHYSICAL PROPERTIES OF MINERALS. 


metallic, it is termed metallic adamantine. Example, 
some varieties of white lead-ore or cerussite. 

b. The degrees of intensity are denominated as follows: 

1. Splendent—when the surface reflects light with great 
brilliancy and gives well-defined images. Example, crys- 
tals of hematite, cassiterite, some specimens of quartz and 

rite. 

Pe. Shining—when an image is produced, but not a well- 
defined image. Example, calcite, celestite. 

3. Glistening—when there is a general reflection from 
the surface, but no image. Example, talc. 

4, Glimmering—when the reflection is very imperfect, 
and apparently from points scattered over the surface. 
Example, flint, chalcedony. 

A mineral is said to be dull when there is a total absence 
of lustre. Hxample, chalk. 


3. COLOR. 
a.) 

1. Kinds of Color.—In distinguishing minerals, both the 
external color and the color of a surface that has been 
rubbed or scratched, are observed. ‘The latter is called the 
streak, and the powder abraded, the streak-powder. 

The colors are either metallic or unmetallic. 

The metallic are named after some familiar metal, as 
copper-red, bronze-yellow, brass-yellow, gold-yellow, steel- 
gray, lead-gray, iron-gray. 

The unmetallic colors used in characterizing minerals are 
various shades of white, gray, black, blue, green, yellow, 
red, and brown. 

There are thus snow-white, reddish-white, greenish- 
white, milk-white, yellowish-white. 

Bluish-gray, smoke-gray, greenish-gray, pearl-gray, ash- 

ray. 

: Velvet-black, greenish-black, bluish-black, grayish-black. 
Azure-blue, violet-blue, sky-blue, indigo-blue. 
Emerald-green, olive-green, oil-green, grass-green, apple- 

green, blackish-green, pistachio-green (yellowish). 

Sulphur-yellow, straw-yellow, wax-yellow, ochre-yellow, 
honey-yellow, orange-yellow. 

Scarlet red, blood-red, flesh-red, brick-red, hyacinth-red, 
rose-red, cherry-red. 


-DIAPHANEITY, LUSTRE, COLOR. &3 


Hair-brown, reddish-brown, chestnut-brown, yellowish- 
brown, pinchbeck-brown, wood-brown. 

A play of colors:—this expression is used when several 
prismatic colors appear in rapid succession on turning the 
mineral. The diamond isa striking example; also pre- 
cious opal. 

Change of colors—when the colors change slowly on turn- 
ing in different positions, as in labradorite. 

Opalescence—when there is a milky or pearly reflection 
from the interior of a specimen, as in some opals, and in 
cat’s-eye. 

Iridescence—when prismatic colors are seen within a 
crystal; it is the effect of fracture, and is common in quartz. 

Tarnish—when the surface colors differ from the inte- 
rior; it is the result of exposure. The tarnish is described 
as irised when it has the hues of the rainbow. 

3. Asterism.—Some crystals, especially the hexagonal, 
when viewed in the direction of the vertical axis, present 
peculiar reflections in six radial directions. ‘This arises 
either from peculiarities of texture along the axial portions, 
or from some impurities. A remarkable example of it is 
that of the asteriated sapphire, and the quality adds much 
to its value as agem. ‘The six rays are sometimes alter- 
nately shorter, indicating the rhombohedral character of 
the crystal. 

4. Phosphorescence.—Several minerals give out light 
either by friction or when gently heated. ‘This property of 
emitting light is called phosphorescence. 

Two pieces of white sugar struck against one another give 
a feeble light, which may be seen in a dark place. ‘The 
same effect is obtained on striking together fragments of 
quartz; and even the passing of a feather rapidly over some 
specimens of zinc-blende is sufficient to elicit light. 

Fluorite is the most convenient mineral for showing phos- 
phorescence by heat. On powdering it and throwing it on 
a plate of metal heated nearly to redness, the whole takes 
on a bright glow. In some varieties the light is emerald- 
green; in others, purple, rose, or orange. A massive fluor, 
from Huntington, Connecticut, shows beautifully the em- 
erald-green phosphorescence. Some kinds of white marble, 
treated in the same way, give out a bright yellow light. 
After being heated for a while the mineral loses its phos- 
phorescence ; but a few electric shocks will, in many cases, 
to some degree restore it again. 


84 PHYSICAL PROPERTIES OF MINERALS. 


6. ELECTRICITY anp MAGNETISM. 


ELECTRICITY.—Many minerals become electrified on ne- 
ing rubbed, so that they will attract cotton and other light 
substances ; and when electrified, some exhibit positive and 
others negative electricity when brought near a delicately 
suspended magnetic needle. ‘The diamond, whether pol- 
ished or not, always exhibits positive electricity, while other 
gems become negatively electric in the rough state, and 
positively only in the polished state. Some minerals, thus 
electrified, retain the power of electric attraction for many 
hours, as topaz, while others lose it in a few minutes. 

Many. minerals become electric when heated, and such 
species are said to be pyroelectric, from the Greek pur, 
fire, and electric. 

A prism of tourmaline, on being heated, becomes polar, 
opposite electricity being developed in the extremities by 
the heat. The prisms of tourmaline have different sec- 
ondary planes at the two extremities. 

Several other minerals have this peculiar electric prop- 
erty, especially boracite and topaz, which, like tourmaline, 
are hemthedral in their modifications. Boracite crystallizes 
in cubes, with only the alternate solid angles similarly re- 
placed (Figs. 39, 40, page 26). Hach solid angle, on heat- 
ing the crystals, becomes an electric pole ; the angles diago- 
nally opposite are differently modified, and have opposite 
polarity. Pyroelectricity has been observed also in crystals 
that are not hemihedral, and in many mineral species. In 
some cases the number of poles is more than two. In preh- 
nite crystals a large series occur distributed over the sur- 
face. 

MAGNETISM.—The name Lodestone is given to those 
specimens of an ore of iron called magnetite which have 
the power of attraction like a magnet; it is common in 
many beds of magnetite. When mounted like a horseshoe- 
magnet, a good lodestone will lift a weight of many pounds. 
This is the only mineral that has decided magnetic attrac- 
tion. But several ores containing iron are attracted by the 
magnet, or, when brought near a magnetic needle, will 
cause it to vibrate ; and moreover, the metals nickel, cobalt, 
manganese, palladium, platinum and osmium, have been 
found to be slightly magnetic. 3 


TASTE AND ODOR. 85 


Many iron-bearing minerals become attractable by the 
magnet after being heated that are not so before heating. 
This arises from a change of part or all of the iron to the 
magnetic oxide. 


7. TASTE anp ODOR. 


Taste belongs only to the soluble minerals. The kinds 

are— 

. Astringent—the taste of vitriol. 

. Sweetish-astringent—the taste of alum. 
Saline—taste of common salt. 
Alkaline—taste of soda. 

Cooling—taste of saltpetre. 
Bitter—taste of Epsom salts. 

. Sour—taste of sulphuric acid. 

Odor is not given off by minerals in the dry, unchanged 
state, except in the case of a few gases and soluble minerals. 
By friction, moistening with the breath, the action of acids, 
_ and the blowpipe, odors are sometimes obtained which are 
thus designated: 

1. Alliaceous—the odor of garlic. Itis the odor of burn- 
ing arsenic, and is obtained by friction, and more distinctly 
by means of the blowpipe, from several arsenical ores. 

2. Horse-radish odor—the odor of decaying horse-radish. 
It is the odor of burning selenium, and is strongly perceived 
when ores of this metal are heated before the blowpipe. 

3. Sulphureous—odor of burning sulphur. Friction 
will elicit this odor from pyrites, and heat from many sul- 
phides. 

4, Fetid—the odor of rotten eggs or sulphuretted hydro- 
gen. It is elicited by friction from some varieties of quartz 
and limestone. 

5. Argillaceous—the odor of moistened clay. It is given 
off by serpentine and some allied minerals when breathed 
upon. Others, as pyrargillite, afford it when heated. 


52D OUR 9 20 


86 CHEMICAL PROPERTIES OF MINERALS. 


TI. CHEMICAL PROPERTIES OF MIN- 
ERALS. 


THE chemical properties of minerals are of two kinds: 
i Those relating to the chemical composition of minerals; 
(2) those depending on their chemical reactions, with or 
without fluxes, including results obtained by means of the 
blowpipe. 


1. CHEMICAL COMPOSITION. 


All the elements made known by chemistry are found in 
minerals, for the mineral kingdom is the source of what- 
ever living beings—plants and animals—contain or use. A 
list of these elements, as at present made out, is contained 
in the following table, together with the symbol for each 
used in stating the composition of substances. These sym- 
bols are abbreviations of the Latin names for the elements. 
A few of these Latin names differ much from the English, 
as follows: 


Stibium Sb = Antimony Kalium K = Potassium 
Cuprum Cu = Copper Argentum Ag = Silver 
Ferrum Fe = Iron Natrium Na = Sodium 
Plumbum Pb = Lead Stannum Sn oer 


Hydrargyrum Hg = Mercury Wolframium W = Tungsten 


TABLE OF THE ELEMENTS. ~ 


Aluminium Al 27.4 | Chlorine Cl 85.5- 
Antimony Sb 120 | Chromium Cr 52 
Arsenic As 75 Cobalt Co 59 
Barium tee toe Copper Cu 63.5 
Beryllium Be 13.8 | Didymium D 95 
Bismuth Bi 210 Erbium E 166 
Boron B 11 Fluorine F 19 
Bromine Br 80 Gallium Ga 70 
Cadmium Caine Gold AX sceaee, 
Cesium Cs 1833 | Hydrogen H 1 
Calcium Ca 40 Indium In 113.4 
Carbon C 12 Jodine I 127 


Cerium Ce 92 Tridium Ir 198 


CHEMICAL COMPOSITION. 





Iron Fe 56 =| Selenium Se 79.4 
Lanthanum La 139 | Silver Ag 108 
Lead Pb 207 | Silicon Si 28 
Lithium Li 7 | Sodium Na 23 
Magnesium Mg 24 | Strontium Sr 87.6 
Manganese Mn 55 | Sulphur 8 32 
Mercury Hg 200 | Tantalum Ta 182 
Molybdenum Mo 96 | Tellurium Te . 128 
Nickel Ni 59 | Thallium Tl 204 
Niobium(Columbium)Nb(Cb)94 | Thorium Lh flor 
Nitrogen N 14 | Thulium dip beryl Ae 
Osmium Os 199 | Tin Sn 118 
Oxygen O 16 | Titanium Ti 50 
Palladium Pd 106 | Tungsten WwW 184 
Phosphorus i& 31 | Uranium U 240 
Platinum Pt 197 | Vanadium V 51.3 
Potassium K 39 | Ytterbium Yb 178 
Rhodium Ro 104 | Yttrium Y 91 
Rubidium Rb 85.4 | Zine Zn 65 
Ruthenium Ru 104 | Zirconium Zr 90 


Germanium is the name of another element. 

The combining weights indicate the proportions in which 
the elements combine. ‘Thus, assuming hydrogen, the 
lightest of the elements, to be 1, or the unit of the series, 
the combining weight of oxygen is 16; of iron, 56; of mag- 
nesium, 24; of sulphur, 32; and so on. When hydrogen 
and oxygen combine it is in the ratio of 2 pounds of hydro- 
gen, or else 1 pound of hydrogen, to 16 pounds of oxygen, 
and two different compounds thus result. When oxygen 
and magnesium combine it is in the ratio of 16 pounds of 
oxygen to 24 of magnesium. Oxygen and iron combine in 
the ratio of 16 of oxygen to 56 of iron; or of 24 of oxygen 
(15 times 16) to 56. Sulphur and oxygen combine in the 
ratio of 32 of oxygen to 32 of sulphur; or of 48 to 32 of sul- 
phur. The combining weights are often called the atomic 
weights. 

The following is the manner of using the symbols: For 
the compound consisting of hydrogen and oxygen in the 
ratio of 2 to 16, the chemical symbol is H,O, meaning 2 of 
hydrogen to 1 of oxygen. (This compound is water.) For 
the compound of oxygen and magnesium just referred to, 
the symbol is MgO; for the two compounds of oxygen and 
iron, FeO, protoxide of iron; Fe,O,, sesquioxide of iron, the 
ratio of 1 to 15 being expressed by 2 to 3; for the two com- 
pounds of sulphur and oxygen, SO, and SO, 


88 CHEMICAL PROPERTIES OF MINERALS. 


- Some of the elements so closely resemble one another 
that their similar compounds are closely alike in: erystalli- 
zation and other qualities, and they are therefore said to be 
asomorphous. 

This is true of iron, magnesium, calcium, and two or 
three other related elements. In one group of compounds 
of these bases, the carbonates, the crystalline form for each 
is rhombohedral, and among them there is a difference of 
less than two degrees in the angle of the rhombohedron. 
Besides a carbonate of calcium, a carbonate of magnesium, 
and a carbonate of iron, there is also a carbonate of calevum 
and magnesium, in which half of the calcium of the first 
of these carbonates is replaced by half an atom of magne- 
sium; and another species in which the base, instead of 
being all magnesium, is half magnesium and half iron. By 
haif is here meant half in the proportion of their combin- 
ing weights. . 

The replacement of one of these elements by the other, 
and similar replacements among other groups of related 
elements, run through the whole range of mineral com- 
pounds. Thus we have sodium replacing potassium, ar- 
senic replacing phosphorus and antimony, and so on. 

In the combinations of oxygen and iron, as illustrated 
above, oxygen is combined with the iron in different pro- 
portions. FeO contains 1 of Fe (iron) to 1 of O (oxygen) 
and Fe,O,, or, as it is often written, FeO,, contains 2 Fe 
tol of O. As the iron in each of these cases satisfies the 
oxygen, it is evident that the iron must be in two different 
states, (1) a protoxide state, and (2) a sesquioxide state. 
One part of iron in this sesquioxide state (= Fe) often 
replaces in compounds one part of iron in the protoxide 
state (or 1Fe), with no greater change of qualities than 
happens in the replacement of iron by magnesium, or cal- 
cium, explained above; or, avoiding fractions, 3 parts of 
Fe in the protoxide state replaces 2Fe in the sesquioxide 
state. Writing Fe for the last 2Fe, the statement becomes 
1 of Fe, replaces 1 of Fe. Aluminium occurs. only in the 
sesquioxide state, and the ordinary symbol of the oxide is 
Al,O,, or AlO,. But it is closely related to iron in the ses- 
quioxide state, so that, using the same mode of expression 
as for iron, 1 of Al replaces 1 of Fe,, or 1 of Mg,, and so 
on. Similarly, writing R for any metal, 1 of B replaces 1 
of R,. Again, in potash (K,O), soda (Na,O), lithia (Li,O), 


CHEMICAL COMPOSITION. 8g 


water (H,O), one of oxygen (O) is combined severally with 
2 of K (potassium), of Na (sodium), of Li (lithium), of hy- 
drogen; and hence 2K, 2Na, 2Li, that is, K,, Na,, Li,, 
may each replace in compounds 1Ca, or 1Mg, etc. 

The elements potassium, sodium, lithium, hydrogen, ot 
which it takes two parts to combine with 1 of oxygen, are 
called monads. Other elements of the group of monads 
are rubidium, cesium, thallium, silver, and also fluorine, 
chlorine, bromine, iodine. Still other elements combining 
by two parts in their oxygen or sulphur compounds, etc., 
are nitrogen, phosphorus, antimony, boron, niobium, tan- 
talum, vanadium and gold. For example, for arsenic there 
are the compounds As,, As,S,, As,O,, As,O,, etc. Another 
characteristic of these elements of the hydrogen, sodium, 
chlorine, and arsenic groups is that the number of equiva- 
lents of the acidic element in the compounds into which 
they enter is, with a rare exception, odd, and of the 1, 3, 5, 
etc., series, and on this account they are called in chemis- 
try perissads ; while the other elements, in whose com- 
pounds their number is of the 1, 2, 3, etc. (or 2, 4, 6) series, 
are called artiads. -An apparent exception exists under 
the artiads in the sesquioxides, but this does not alter the 
general character of the series. 

The facts above cited sustain the general statement that 
Ca,, Mg,, Mn,, Zn,, Fe,, Al, Fe, Mn, have equivalent com- 
bining values, and hence in minerals often replace one an- 
other; and so also Ca, Mg, Mn, Zn, Fe, K,, Na,, Li,, H,, 
may replace one another. Similarly, also, As,, or Sb,, re- 
places 8 in some minerals. 

With reference to the classification of minerals the ele- 
ments may be conveniently divided into two groups: (1) 
the Acidic, and (2) the Basic. The former includes oxy- 
gen and the elements which were termed the acidifiers and 
acidifiable elements in the old chemistry. ‘They are those 
which have been called in mineralogy the mineralizing ele- 
ments, since they are the elements which are found com- 
bined with the metals to make them ores, that is, to miner- 
alize them. ‘The basic are the rest of the elements. ‘The 
groups overlap somewhat, but this need not be dwelt upon 
here. 

The more important of the acidic elements are the fol- 
lowing: oxygen, fluorine, chlorine, bromine, iodine, sul- 
phur, selenium, tellurium, boron, chromium, molybdenum, 


90 CHEMICAL PROPERTIES OF MINERALS. 


tungsten, phosphorus, arsenic, antimony, vanadium, nitro- 
gen, tantalum, niobium, carbon, silicon. 

Again, among the conpounds of these elements occurring 
in the mineral kingdom there are two grand divisions, the 
binary and the ¢ernary. ‘The binary consist of one or 
more elements of each of the acidic and basic divisions, and 
‘the ternary of one or more elements of each of these two 
classes, along with oxygen, fluorine, or sulphur as a third. 
The binary include the sulphides, arsenides, chlorides, fluor- 
ides, oxides, etc., and the ternary the sulphates, chromates, 
borates, arsenates, phosphates, silicates, carbonates, etc., and 
also the sulph-arsenites and sulph-antimonites, in which a 
basic metal (usually lead, copper, silver) is combined with 
arsenic or antimony and sulphur. 

The following are examples of the symbols of binary and 
ternary compounds : 


1. Binary. 


1. Sulphides, Selenides.—Ag,S = silver sulphide; Ag,Se 
= silver selenide; PbS = lead sulphide; ZnS = zine sul- 
phide; FeS, = iron disulphide. 

2. Fluorides, Chlorides, etc.—CaF, = calcium fluoride; 
AgCl = silver chloride; AgBr = silver bromide; Agl = © 
silver iodide; NaCl = sodium chloride (common salt). 

3. Ozides.—Al,O, = 3(Al; O) = aluminium sesquioxide; 
As,O, = arsenic trioxide; As,O, = arsenic pentoxide; BaO 
= barium oxide; Be,O, = beryllium oxide; B,O, = boron 
trioxide (boracic acid) ;.CaO = calcium oxide (lime); CeO 
= ceria; CO, = carbon dioxide (carbonic acid); OrO, = 
chromium trioxide (chromic acid); Cu,O = copper subox- 
ide; CuO = copper oxide; DiO = didymia; H,O = hy- 
drogen oxide (water); FeO = iron oxide; Fe,O, = iron 
sesquioxide; PbO = lead oxide; Li,O = lithium oxide; 
MgO = magnesium oxide; MnO = manganese oxide; 
Mn,0, = manganese sesquioxide; MnO, = manganese di- 
oxide; P,O, = phosphorus pentoxide; K,O = potassium 
oxide; S10, = silicon dioxide (silica); Na,O = sodium 
oxide; SrO = strontium oxide; SO, = sulphur dioxide 
(sulphurous acid); SO, = sulphur trioxide; SnO, = tin 
dioxide ; ‘'m,O, = thulia; V,O0, = vanadium pentoxide 
(vanadic acid); WO, = tungsten trioxide (tungstic acid); 


CHEMICAL COMPOSITION. 91 


Yb,0, = ytterbia; ZnO = zinc oxide; ZrO, = zirconium 
dioxide. 

The composition of these compounds may be obtained 
from the table of combining weights, page 86. For exam- 
ple, with reference to the first of them (Ag,S), the table 
gives for the combining weight of silver (Ag), 108, and for 
that of sulphur, 32. ‘The elements exist in the compound 
therefore in the proportion of 216 to 32, and from it the 
composition of a hundred parts is easily deduced. 

If the formula were (Ag,, Pb)S, signifying a silver-and- 
lead sulphide, and if the silver and lead were in the ratio 
of 1 to 1, then once the combining weight of silver is taken ; 
that is, 108, and half the atomic weight of lead, which is 
103°5; and the sum of these numbers, with 32 for the sul- 
phur, expresses the ratio of the three ingredients. 

For Al,O, we find the combining weight of aluminium 
27:4; doubling this for Al, makes 54°8. Again, for oxygen, 
we find 16; and three times 16 is 48. 54°8 to 48 is there- 
fore the ratio of aluminium to the oxygen in Al,O,, from 
which the percentage proportion may be obtained. 


2. Ternary Oxygen Compounds. 


Silicates.—Of these compounds there are two prominent 
groups. In one of these groups the general formula is 
RO,Si, and in the other R,O,Si. In both of these formu- 
las, R stands for any basic elements in the protoxide state, 
as Oa, Mg, Fe, etc., either alone or in combination. If 
the basic element is Mg (magnesium) they become Mg0O,Si, 
and MgO,Si (sometimes also written MgO -+ SiO, and 
2MgO + Si0,, this being the old style). In the first of 
these formulas the combining values of the basic element 
R and the acidic element or silicon, as measured by their 
combinations with oxygen, are in the proportion of 1 to 2, 
for R stands for an element in the protozide state, while Si 
stands for silicon, which is in the dioxide state, its oxide 
being a dioxide; and hence the minerals so constituted are 
called isilicates. In the second of these formulas this 
ratio is 2 to 2, or 1 to 1, and hence these are called Unisili- 
cates. 'The second style of formula (the old style) has the 
advantage of expressing the bases and acids obtained in an 
analysis and mentioned in the tables of percentage results 


92 CHEMICAL PROPERTIES OF MINERALS. 


Multiplying these formulas by 3, they become R,O,Si,, 
and (2R,)O,,8i,; and the same composition is expressed. 
In this form the substitution of sesquioxide bases for pro- 
toxide may be indicated: thus, R,RO,,Si, signifies that 
half of the 2R, is replaced by Al or Fe, or some other ele- 
ment in the sesquioxide state. 

There are also some species in which the ratio is 1 to less 
than 1, and these are called Swdsilicates. 

The ratio here referred to is the oxygen ratio or the 
quantivalent ratio. 

The other ternary compounds require no special remarks 
in this place. 


2, CHEMICAL REACTIONS. 


1. Zrials in the wet way. 


1. Test for Carbonates.—Into a test-tube put a little hy- 
drochloric acid diluted with one half water, and add a 
small portion in powder of the mineral. With a carbonate, 
there will be a brisk effervescence caused by the escape of 
carbonic dioxide (carbonic acid), when heat is applied, if 
not before. With calcium carbonate no heat or pulveriza- 
tion is necessary. 

2. Test for Gelatinizing Silica.—Some silicates, as neph- 
elite and many zeolites, when powdered and treated with 
strong hydrochloric acid, are decomposed, and deposit the 
silica in the state of a jelly. ‘The experiment may be per- 
formed in a test-tube, or small glass flask. Sometimes the 
evaporation of the liquid nearly to dryness is necessary in 
order to obtain the jelly. Some silicates do not afford the 
jelly unless they have been previously ignited before the 
blowpipe, and some gelatinizing silicates lose the power on 
ignition. 

Test for Soda in some Silicates.—When nephelite is 
treated with hydrochloric acid the solution deposits, on 
evaporation, cubes of common salt (sodium chloride); and 
in this and some other sodium silicates, if the hydrochloric 
solution is treated with a concentrated solution of uranium 
acetate, yellow tetrahedrons of sodium uranate are formed. 

3. Decomposability of Minerals by Acids.—To ascertain 
whether a mineral is decomposable by acids or not, it is 
very finely powdered and then boiled with strong hydro- 


CHEMICAL REACTIONS. 93 


chloric acid, or, in case of many metallic minerals, with nit- 
ric acid. In some cases (as leucite, scapolite, labradorite, 
etc.), where no jelly is formed, there is a deposit of silica in 
a pulverulent state. With the sulphides and nitric acid > 
there is often a deposit of sulphur, which usually floats upon 
the surface of the fluid as a dark spongy mass; with hydro- 
chloric acid and some sulphides, sulphuretted hydrogen is 
given off. Some oxides, and also some sulphates and many 
phosphates, are soluble entirely without effervescence. 
But many minerals resist decomposition with nitric acid as 
wellas hydrochloric. It is sometimes difficult to tell whether 
a mineral is decomposed with the separation of the silica or 
whether it is unacted upon. In such a case a portion of 
the clear fluid is neutralized by soda (sodium carbonate), 
and if anything has been dissolved it will usually be pre- 
cipitated. 

A, Test for Lime in Apatite—A solution of apatite in 
hydrochloric acid, if treated with sulphuric acid, deposits 
gypsum freely. 

5. Test for Titanium in Menaccanite.—The pulverized 
mineral, heated with hydrochloric acid, is slowly dissolved ; 
the yellow solution, filtered from the undecomposed mineral 
and boiled with the addition of tin-foil, assumes a beautiful 
blue or violet color—a result not obtained with hematite, 
the mineral it most resembles. 

6. Test for Fliuorine.—Most fluorides (as fluorite, cryolite, 
etc.) are decomposed by strong heated sulphuric acid, and 
give out fluorine which will etch a glass plate in reach of 
the fumes. ‘The trial may be made in a lead cup, and the 
glass put over it as a loose cover. 

v7. Test for Native Iron.—Dilute nitrate of copper de- 
posits copper ona clean plate of iron. 

8. Test for Phosphoric Acid in Apatite, etc.—A concen- 
trated nitric-acid solution of ammonium molybdate acts on 
apatite and deposits yellow octahedrons or dodecahedrons 
of ammonium phosphomolybdate; and a drop of the solu- 
tion will produce this result with the apatite of a thin sec- 
tion prepared for microscopic study. 


2. Trials with the Blowpipe. 


The blowpipe, in its simplest form, is merely a bent tube 
of small size, eight to ten inches long, terminating at one 


94 CHEMICAL PROPERTIES OF MINERALS. 


end ina minute orifice. It is used to concentrate the flame 
on a mineral, and this is done by blowing through it while 
the smaller end is just within the flame. 

The annexed figure represents the form commonly em- 
ployed, except that it often has a trumpet-shaped mouth- 
piece. It contains an air-chamber (0) to receive the moisture 
which is condensed in the tube during the blowing; the 
moisture, unless thus removed, is often blown through the 
small aperture and interferes with the experiment. The 
jet, jf, is movable, and it is desirable that it should be 

made of platinum, in order that it may he 
4% cleaned when necessary, either by high heating 
or by immersion in an acid. 

In using the blowpipe it is necessary to 
breathe and blow at the same time, that the oper- 
ator may not interrupt the flame in order to take 
breath. Though seemingly absurd, the neces- 
sary tact may easily be acquired. Let the stu- 
dent first breathe a few times through his nos- 
trils while his cheeks are inflated and his mouth 
closed. After this practice let him put the 
blowpipe to his mouth and he will find no diffi- 
culty in breathing as before while the muscles 
of the inflated cheeks are throwing the air they 
contain through the blowpipe. When the air is 
nearly exhausted the mouth may again be filled 
through the nose without interrupting the pro- 
cess of blowing. 

The flame of a candle, or a lamp with a large wick, may 
be used; and when so, it should be bent in the direction the 
flame is to be blown. But itis far better, when gas can be 
had, to use a Bunsen’s burner. 

The flame has the form of a cone, yellow without and 
blue within. The heat is most intense just beyond the ex- 
tremity of the blue flame. In some trials it is necessary 
that the air should not be excluded from the mineral during 
the experiment, and when this is the case the ow/er flame 
is used. The outer is called the oxidizing flame (because 
oxygen, one of the constituents of the atmosphere, com- 
bines in many cases with some parts of the assay, or sub- 
stance under experiment), and the inner the reducing flame. 
In the latter the carbon and hydrogen of the flame, which 
are in a high state of ignition, and which are enclosed from 





CHEMICAL REACTIONS. 95 


the atmosphere by the outer flame, tend to unite with the 
oxygen of any substance that is inserted in it. Hence sub- 
stances are reduced in it. 

The mineral is supported in the flame either on charcoal ; 
or by means of steel forceps (as in the annexed figure) with 

































































platinum extremities (ab), opened by pressing on the pins 
Pp p; or on platinum wire or foil. 

To ascertain the fusibility of a mineral, the fragment for 
the platinum forceps should not be larger than the head of 
a pin, and, if possible, should be thin and oblong, so that 
the extremity may project beyond the platinum. The fu- 
sible metals alloy readily with platinum. Hence com- 
pounds of lead, arsenic, antimony, etc., must be guarded 
against. ‘These compounds are tested on charcoal. The 
forceps should not be used with the fluxes, but instead 
either charcoal or the platinum wire or foil. 

The charcoal should be firm and well burnt; that of soft 
wood is the best. It is employed especially for the reduc- 
tion of oxides, in which the presence of carbon is often 
necessary, and also for observing any substances which may 
pee off and be deposited on the charcoal around the assay. 

hese coatings are usually oxides of the metals, which are 
formed by the oxidation of the volatile metals as they issue 
from the reduction-flame. 

The platinum wire is employed in order to observe the 
action of the fluxes on the mineral, and the colors which 
the oxides impart to the fluxes when dissolved in them. 
The wire used is No. 27. This is cut into pieces about 
three inches long, and the end is bent into a small loop, in 
which the flux is fused. - This makes what is called a bead. 
When the experiment is complete the beads are removed by 
uncoiling the loop and drawing the wire through the finger- 
nails. After use for awhile the end breaks off, because pla- 
tinum is acted upon by the soda, and then a new loop has 
to be made. Dilute sulphuric acid will remove any of the 
flux that may remain upon it after a trial has been made. 

Glass tube is employed for various purposes. It should 
be from a line to afourth of an inch in bore. It is cut into 


96 CHEMICAL PROPERTIES OF MINERALS. 


pieces four to six inches long, and used in some cases with 
both ends open, in others with one end closed. In the 
closed tube, either heated directly over the Bunsen burner, 
or with the aid of the blowpipe, volatile substances in the 
assay are vaporized and condensed in the upper colder part 
of the tube, where they may be examined by a lens if neces- 
sary, or by further heating. The odor given off may also 
be noted; also the acidity of any fumes by inserting a small 
strip of litmus paper in the mouth of the tube, for acids 
redden litmus paper. The closed tube is used to observe 
all-the effects that may take place when a substance is 
heated out of contact with the air. In the open tube the 
atmosphere. passes through the tube in the heating, and so 
modifies the result. The assay is placed an inch or an inch 
and a quarter from the lower end of the tube; the tube 
should be held nearly horizontally, to prevent the assay 
from falling out. The strength of the draught depends 
upon the inclination of the tube, and in special cases it 
should be inclined as much as possible. 

The most common fluzes are borax (sodium biborate), 
salt of phosphorus (sodium and ammonium phosphate), and 
soda (sodium carbonate, either the carbonate or bicarbon- 
ate of soda of the shops). These substances, when fused 
and highly heated, are very powerful solvents for metallic 
oxides. ‘They should be pure preparations. The borax 
and soda are much the most important. In using the pla- 
tinum wire, the loop may be highly heated, and then a por- 
tion of the borax or soda may be taken up by it, and by 
successive repetitions of this process the requisite amount of 
the flux may be obtained on the wire. ‘Then, by bringing 
the melted flux of the loop into contact with one or more 
grains of the pulverized mineral, the assay is made ready 
for the trial. With soda and quartz a perfectly clear glob- 
ule is obtained, cold as well as hot, if the flux is used in 
the right proportion. Some oxides impart a deep and 
characteristic color to a bead of borax. In other cases the 
color obtained is more characteristic when salt of phos- 
phorus isemployed. The color obtained in the outer flame 
is often different from that which is obtained in the inner 
flame. ‘The beads are sometimes transparent and some- 
times opaque. If too much substance is employed the 
beads will be opaque when it is desired that they should be 
transparent, and in such cases the experiment should be re- 


CHEMICAL REACTIONS. 7 97 


peated with less substance. In many cases pulverized min- 
eral and the flux, a little moistened, are mixed together into 
a ball upon charcoal, especially in the experiments with 
soda. 

In the examination of sulphides, arsenides, antimonides 
and related ores, the assay should be roasted before using a 
flux, in order to convert the substance into an oxide. This 
is done by spreading the substance out on a piece of char- 
coal and exposing it to a gentle heat in the oxidizing flame. 
The sulphur, arsenic, antimony, etc. then pass off as ox- 
ides in the form of vapors, leaving the non-volatile metals 
behind as oxides. The escaping sulphurous acid gives the 
ordinary odor of burning sulphur ; arsenous acid, from ar- 
senic present, the odor of garlic, or an alliaceous odor ; se- 
lenous acid, from selenium present, the odor of decaying 
horse-radish ; while antimony fumes are dense white, and 
have no odor. 

The following is the scale of fusidility which has been 
adopted, beginning with the most fusible: 

1. STIBNITE.—F usible in large pieces in the candle flame. 

2. NATROLITE.—Fusible in small splinters in the candle 
flame. 

3. ALMANDINE, or bright-red GARNET.—Fusible in large 
pieces with ease in the blowpipe flame. 

4, ACTINOLITE.—Fusible in large pieces with difficulty 
in the blowpipe flame. 

5. ORTHOCLASE, or common feldspar. Fusible in small 
splinters with difficulty in the blowpipe flame. 

6. BronzitE. Scarcely fusible at all. 

The color of the flame is an important character in connec- 
tion with blowpipe trials) When the mineral contains 
sodium the color of the flame is deep yellow, and this is 
generally true in spite of the presence of other related ele- 
ments. When sodium (or soda) is absent, potassium (or 
potash) gives a pale violet color; calciwm (or lime) a pale 
reddish yellow; lithtwm, a deep purple-red, as in lithia- 
mica; strontium, a bright red, this element being the usu- 
al source of the red color in pyrotechny; copper, emerald 
green; phosphates, bluish green; boron, yellowish green; 
copper chloride, azure-blue. Beads should be examined by 
daylight only, and should be held in such position that the 
color is not modified by green trees or other bright objects 
when examined by transmitted light. Colored flames are 

7 


98 CHEMICAL PROPERTIES OF MINERALS. 


seen to best advantage when some black object is beyond 
the flame in the line of vision. 

It is also to be noted, in the trials, whether the assay 
heats up quietly or with decrepitation; whether it fuses 
with effervescence or not, or with intumescence or not; 
whether it fuses to a bead which is transparent, clouded, or 
opaque; whether blebby (containing air-bubbles) or not; 
whether scoria-like or not. 

Testing for Water.—The powdered mineral is put at the 
bottom of a closed glass tube, and after holding the ex- 
tremity for a moment in the flame of a Bunsen’s burner, 
moisture, if any is present, will have escaped and be found 
condensed on the inside of the tube, above the heated 
portion. Litmus or turmeric paper is used to ascertain if 
the water is acid or alkaline, acids changing the blue of lit- 
mus paper to red, and alkalies the yellow of turmeric paper 
to brown. 

Testing for aw Alkali.—lf the fragment of a mineral, 
heated in the platinum forceps, contains an alkali, it will 
often, after being highly heated, give an alkaline reaction 
when placed, after moistening, on turmeric paper, turning 
it brown. ‘This test is applicable to those salts which, on 
heating, part with a portion of their acid and are rendered 
caustic thereby. Such are the carbonates, sulphates, ni- 
trates, and chlorides of the alkaline metals. 

Testing for Alumina or Magnesia.—Cobalt nitrate, in 
solution, is used to distinguish an infusible and colorless 
mineral containing aluminium from one containing mag- 
nesium. A fragment of the mineral is first ignited, and 
then wet with a drop or two of the cobalt solution and 
heated again. The aluminium mineral will assume a blue 
color, and the magnesium mineral a pale red or pink. 

Any fusible silicate, when moistened with cobalt nitrate 
and ignited, will assume a blue color, hence this test is only 
decisive in testing infusible substances. 

Infusible zinc compounds, when moistened with cobalt 
nitrate, assume a green color. 

Testing for Litihium.—sSome lithium minerals give the 
bright purple-red flame if simply heated in the platinum 
forceps. In other cases mix the powdered mineral with 
one part of fluorite and one of potassium bisulphate. Make 
the whole into a paste with a little water, and heat it on 
the platinum wire in the blue flame. 


CHEMICAL REACTIONS. 99 


Testing for Boron.—When the bright yellow-green of 
boron is not obtained directly on heating the mineral con- 
taining it, one part of the powdered mineral should be 
mixed with one part of powdered fluorite and three of po- 
tassium bisulphate; and then treated as in the last. The 
green color appears at the instant of fusion. 

Testing for Fiuworine.—To detect fluorine in fluorides 
mix a little of the powdered substance with potassium bi- 
sulphate, put the mixture in a closed glass tube and fuse 
gently. ‘The bisulphate gives off half of its sulphuric acid 
at a high temperature, which acts powerfully on anything 
it can attack. If a fluoride is present, hydrofluoric acid 
will be given off, and the walls of the tube will be found 
roughened and etched when the tube is broken open and 
cleaned after the experiment. If a silicate containing 
fluorine be powdered and mixed with previously fused salt 
of phosphorus, and heated in the open tube by blowing the 
flame into the lower end of the tube, hydrofluoric acid is 
given off, and the tube is corroded just above the assay. 

Silicates.—Nearly all silicates undergo decomposition 
with salt of phosphorus, setting free the silica, forming a 
bead which is clear while hot and has a skeleton of silica 
floating init. The bead is sometimes clear also when cold. 

Jron.—Minerals containing much iron produce a mag- 
netic globule when highly heated. Usually the reducing 
flame is required, and sometimes the use of soda. With 
borax iron gives a bead with the oxidizing flame which is 
yellow while hot, but colorless on cooling, and which in the 
reducing flame becomes bottle-green. 

Cobalt.—Minerals containing cobalt afford, with borax, a 
beautiful blue bead. If sulphur or arsenic is present it 
should be first roasted off on charcoal. 

Nickel.—In the oxidizing flame with borax, the bead is 
violet when hot, and red-brown on cooling. In the reduc- 
ing flame the glass becomes gray and turbid from the sepa- 
ration of metallic nickel, and on long blowing, colorless. 
The reaction is obscured by the presence of cobalt, iron, 
and copper. 

Manganese.—With borax in the oxidizing flame, the bead 
is a deep violet-red, and almost black if too much of the 
mineral is used. ‘To see the color, examine by transmitted 
light. With soda in the same flame the opaque bead is 
bluish green, 


100 CHEMICAL PROPERTIES OF MINERALS. 


Chromium.—With borax, both in the oxidizing and re- 
ducing flame, the bead is bright emerald-green. 

Titanium.—Titanium oxide with salt of phosphorus on 
platinum wire in O.F. dissolves to a clear glass, which, if 
much is present, becomes yellow while hot and colorless on 
cooling; but in R.F. the hot globule obtained in O.F. red- 
dens and assumes finally a beautiful violet color. On char- 
coal with tin the glass becomes violet if there is not too 
much iron present. 

Zince.—Zine and some of its compounds when heated 
cover the charcoal with zinc oxide, which is yellow while 
hot, but white on cooling; and this coating, if wet with 
cobalt solution and then heated, assumes a fine yellowish 
green color which is most distinct when cold. 

Lead, copper, tin, silver, when characterizing a mineral, 
give with soda in the reducing flame minute metallic 
globules, which are malleable, or may be cut with a knife; 
they can be distinguished by their well-known physical 
properties. When two or more of these metals occur to- - 
gether, or iron is also present, the globules consist usually 
of an alloy of the metals. | 

Lead.—When the mineral is treated with soda on char- 
coal in the oxidizing flame, the yellow oxide coats the char- 
coal around the assay. 

Copper.—The flame is colored, in most cases, bright 
green. With borax or salt of phosphorus in the reducing 
flame the bead is red. In the oxidizing flame the bead is 
green when hot, and becomes blue or greenish blue on cool- 
ing. | 

Mercury.—Heated in the closed tube with soda, a sub- 
limate of metallic mercury covers the inside of the tube. 

Silver.—lf the silver is in very small quantities, as in 
argentiferous galena, the assay is put into a little cup made 
of bone-ashes (bone burnt white and finely pulverized), and 
subjected to the oxidizing flame; the lead is oxidized and 
sinks into the bone-ashes, leaving the silver a brilliant 
globule on the cupel. Before cupellation it is often neces- 
sary to melt the assay together with some borax and pure 
lead in a hole on charcoal. By this process the sand and 
impurities are removed, and a globule of lead is obtained 
which contains all the silver, and which may be separated 
from the slag and be oxidized as above. 

Arsenic.—In the closed tube arsenic sublimes and coats 


CHEMICAL REACTIONS. 101 


the tube with brilliant grains, ora crust, of metallic arsenic. 
If the mineral contains sulphur as well as arsenic, subli- 
mates of the yellow and red arsenic sulphides (orpiment 
and realgar) are often formed. In the open tube a subli- 
mate of white arsenous acid is formed, which condenses in 
bright crystals on the walls of the tube, and a strong garlic 
odor is given off. On charcoal the alliaceous odor is at once 
perceptible. 

Antimony.—In the closed tube, when sulphur is present, 
the assay yields a sublimate which is black when hot, 
brown-red when cold. In the open tube dense white 
vapors are given off and a white amorphous sublimate covers 
the inside of the tube, which, for the most part, does not 
‘volatilize when reheated. On charcoal the assay yields 
dense, white, inodorous fumes. 

Tellurium.—tin the open tube a white or grayish subli- 
mate is obtained, which may be fused to clear, colorless 
drops. On charcoal a white coating is produced, and the 
reducing flame is colored green. 

Suiphur.—All sulphates and other sulphur-bearing min- 
erals, when heated on charcoal with soda, produce a dark, 
yellowish-brown sulphide of sodium; and if a fragment of 
this is moistened and placed on a polished plate of silver, 
it turns it immediately brownish black, or black. Pure 
soda, and aflame wholly free from sulphur, is needed for 
the trial, since the least trace of sulphur in either vitiates 
the result. Many sulphides give fumes of sulphur on char- 
coal. The higher sulphides afford these fumes in a closed 
tube. ‘The others afford fumes of sulphurous acid in an 
open tube, which redden a moistened blue litmus paper 
placed in the upper end of the tube. 

Selenitwm.—Selenium and many selenides afford a steel- 
gray sublimate in an open tube, which at the upper edge 
appears red. On charcoal brown fumes are given off with 
an odor like that of decaying horse-radish. 

Chlorides.—If a bead of borax be saturated with copper 
oxide, and then dipped into the powder of a substance 
which is to be tested for chlorine, a chloride of copper is 
formed which imparts an azure-blue color to the flame if 
any chlorine is present. If dissolved in water or nitric 
acid a little silver nitrate produces a dense white precipi- 
tate of silver chloride. 

Nitrates.—A nitrate, if fused on charcoal, will deflagrate 


102 CHEMICAL PROPERTIES OF MINERALS, 


with brilliancy, owing to the decomposition of the nitrate 
and the union of its oxygen with the carbon. 

Phosphates.—Phosphates give a dirty green color to the 
blowpipe flame. ‘The color is more distinct if the sub- 
stance is first moistened with sulphuric acid. If a phos- 
phate is pulverized and heated in a closed glass tube with 
some bits of magnesium wire, the phosphoric acid is re- 
duced; and when the fusion is moistened with water the 
very disagreeable odor of phosphuretted hydrogen is ob- 
tained. 

For a full account of blowpipe reactions recourse should 
be had to a treatise on the blowpipe. The best American 
works on the subject are Prof. G. J. Brush’s ‘‘ Manual of 
Determinative Mineralogy, with an Introduction on Blow- 
pipe Analysis,” and H. B. Cornwall’s ‘‘ Manual of Blow- 
pipe Analysis.” 

In the description of species beyond, the following abbre- 
Viations are used in speaking of blowpipe reactions: 

B.B. = before the blowpipe; O./. = oxidizing flame; 
Rk. F.= reducing flame, 


CLASSIFICATION. 103 


IV. DESCRIPTIONS OF MINERALS. 


CLASSIFICATION. 


Some of the prominent points in the classification of 
minerals adopted in the following pages are given in con- 
nection with the remarks on chemical composition, page 
79. 

Many instructors in the science, and most of those who 
consult a work on Mineralogy for practical purposes, pre- 
fer an arrangement of the ores which groups them under 
the head of the metal prominent in their constitution. 
‘The method of grouping mineral species according to the 
basic element has therefore been here, to a large extent, 
followed. An exception has been made in the case of the 
silicates, because it is with them almost impracticable, on 
account of the number of basic elements they often con- 
tain ; and, moreover, not more than. half a dozen useful 
ores exist among them. The silicates therefore, which in- 
clude the larger part of all minerals, make together one of 
the grand divisions in the classification, and they are pre- 
sented according to their natural groups, in the same order 
as in the larger mineralogy. 

The prominent subdivisions in the classification are as 
follows ; 

I. THE AcrIDIc DIVISION, including the acidic elements 
occurring native, and the native compounds of the acidic 
elements with one another. 

IJ. THE BAsic DIVISION, including the basic elements 
occurring native, and the native binary and ternary com- 
pounds of the basic elements—the silicates excepted. 

III. SrzrcA and the SILICATES. 

IV. Tur HyprocarBon CoMPOUNDS, including min- 
eral oils, resins, wax, and coals. 

The following are the chief subdivisions under these 
heads: 


I. Acrtp1c DIvIsIon. 


1. Sulphur Group.—The chief oxide a trioxide, its for- 
mula RO,. Includes Sulphur and sulphur oxides; Tel- 


104 DESCRIPTIONS OF MINERALS. 


lurium and tellurium oxides; Molybdenum sulphide and 
oxide; Tungsten oxide. 

2. Boron Group.—The chief oxide a trioxide, its for- 
mula R,O,. Includes compounds of Boron with oxygen. 

3. Arsenic Group.—The chief oxide a pentoxide, its 
formula R,O,. Includes Arsenic and arsenic sulphides 
and oxides ; Antimony and antimony sulphide, arsenide and 
oxides; Bismuth and bismuth sulphide, telluride and oxide. 

4, Carbon Group.—The chief oxide a dioxide, its for- 
mula RO, Includes Carbon (Diamond, Graphite) and 
carbon dioxide. (Quartz, SiO,, belongs here chemically, 
but is placed with the Silicates. ) 


II. BAstc DIvIsIon. 


Gold ; Silver ; Platinum and Iridium; Palladium ; Quick- 
silver; Copper; Lead ; Zinc; Cadmium; Tin; Titanium;. 
Cobalt and Nickel; Uranium; Iron; Manganese; Alu- 
minium; Cerium, Yttrium, Lanthanum, Didymium and 
Erbium ; Magnesium; Calcium; Barium and Strontium ; 
Potassium and Sodium ; Ammonium ; Hydrogen. 


IiI. Srzr1cA AND SILICATES. 


1. Silica. 
2. Anhydrous Silicates. 
1. Bisilicates. 
2. Unisilicates. 
3. Subsilicates. 
3. Hydrous Silicates# 
1. General section of Hydrous Silicates. 
2. Zeolite section. 
3. Margarophyllite section. 


IV. HyprocARBON COMPOUNDS. 
1. Oils, Resins, Wax. 
2. Asphaltum, Coals. 

GENERAL REMARKS ON ORS. 


An ore, in the mineralogical sense of the word, is a 
mineral compound in which a metal is a prominent constit- 
uent. In the miner’s use of the term itis a mineral sub- 
stance that yields, by metallurgical treatment, a valuable 


GENERAL REMARKS ON ORES. 105 


metal, and especially when it profitably yields such a 
metal. In the former sense, galena, the common ore of 
lead, is, if it contains a little silver, an argentiferous lead- 
ore; while, in the latter, if there is silver enough to make 
its extraction profitable, it is a silver-ore. Further than 
this, where a native metal, or other valuable metallic min- 
eral, is distributed intimately through the gangue, the 
mineral and gangue together are often called the ore of the 
metal it produces. 

We have beyond to do with ores only in the mineralogi- 
cal sense. 

Ores are compounds of the metals, not metals in the 
native state. The more common kinds are compounds of 
the metals with Sulphur (sulphides) ; with Arsenic (arsen- 
nides) ; with Sulphur and Arsenic (sulph-arsenides) ; with 
sulphur in ternary combination along with arsenic, anti- 
mony or bismuth (making compounds called sulph-arse- 
nites, sulph-antimonites, sulpho-bismutites) ; with Selenium 

selenides) ; with Telluriwm (tellurides); with Oxygen 
oxides); with Chlorine, Iodine, or Bromine (chlorides, 
iodides, or bromides); with oxygen in ternary combina- 
tion with carbon (making carbonates) ; with Sulphur (mak- 
ing sulphates); with Arsenic (making arsenates) ; with 
Phosphorus (making phosphates) ; with Silicon (making 
silicates). 

Gold and platinum are, with rare exceptions, found only 
native, or intimately mixed in essentially the pure state 
with some metallic minerals. ‘Tellurium is the only acidic 
element that occurs combined with gold in nature. 

Silver is found in the state of sulphide, antimonide, 
selenide, telluride, sulph-arsenites and sulph-antimonites, 
but never as oxide or in oxygen ternary compounds. 

Quicksilver occurs in the state of sulphide (the common 
ore) ; also in that of selenide and sulph-arsenites. 

Copper and lead occur in the state of sulphides (common 
ores), and also in all the binary and ternary states men- 
tioned above. 

Zinc is known in the state of sulphide (very common), 
oxide, carbonate, sulphate, silicate (all, excepting the 
sulphate, valuable as ores) ; and Cadmium in that of sul- 
phide only. 

7in occurs in the state of oxide (the common ore) and 
sulphide. 7 


106 DESCRIPTIONS OF MINERALS. 


Cobalt and Nickel occur in the states of sulphide, arse- 
nide, sulph-arsenides, antimonide, oxide, sulphate, arsenate, 
carbonate; and nickel in that also of a silicate. 

Tron occurs in the state of sulphide (very common, but 
not useful as an ore of iron); of arsenide, sulph-arsenide; 
of oxide (the common ores of iron); carbonate (onetHt ore), 
sulphate, arsenate, phosphate, silicate. 

Manganese occurs in the state of sulphide (rare), arse- 
nide (rare), oxide (the common ores), carbonate, sulphate, 
phosphate, silicate. 


its MINERALS CONSISTING OF THE ACIDIC 
ELEMENTS. 


Oxygen might properly be included in this section, since 
it occurs native in the atmosphere mixed with nitrogen, ' 
constituting 21 per cent of it. But this mention of it is 
all that is necessary. ‘The ternary compounds, in which, 
as in sulphuric acid, hydrogen is the basic element, are 
here included. Chlorine, bromine, and iodine do not occur 
native, and neither do their oxides, nor any compounds 
with acidic elements, and hence these elements are not 
represented under this division. The same is true of 
selenium and chromium of the sulphur group, and of vana- 
dium, tantalum, and niobium of the arsenic group. 


1. SULPHUR GROUP. 
Native Sulphur. 


Orthorhombic. In acute octahedrons, and secondaries 
to this form, with imperfect octahedral cleavage; 1,1 
(in same Sea lp = 106° 25’ and 85° 07’; 1A1 (over 
base) = 143° 237. Also massive. 

Color and streak sulphur-yellow, 
sometimes orange-yellow. Lustre 
resinous. ‘Transparent to translu- 
cent. Brittle. H. = 1.5 — 2.5. 
G. = 2.07. Burns with a blue flame 
and sulphurous odor. Ina closed 
tube wholly volatilized and redepos- 
ited on the walls of the tube. 

Native sulphur is often contaminated with clay or bitu- 





MINERALS CONSISTING OF THE ACIDIC ELEMENTS. 107 


men. Sometimes contains selenium, and has then an 
orange-yellow color. 

Diff. It is easily distinguished by its burning with a blue 
flame, and the sulphur odor then afforded. 

Obs. The great repositories of sulphur are either beds of 
gypsum and the associate rocks, or the regions of active or 
extinct volcanoes. In the valley of Noto and Mazzaro in 
Sicily, at Conil near Cadiz in Spain, Bex in Switzerland, 
and Cracow in Poland, it occurs in the former situation. 
Sicily and the neighboring volcanic islands, Vesuvius and 
the Solfatara in its vicinity, Iceland, Teneriffe, Java, Ha- 
wail, New Zealand, Deception Island, and most active vol- 
canic regions, afford more or less sulphur. 

On the Potomac, twenty-five miles above Washington, 
sulphur has been found associated with calcite in a gray 
compact limestone; sparingly about springs where hydrogen 
sulphide is evolved, in New York and elsewhere; in cavities 
where iron sulphides have decomposed, and in many coal- 
mines. Abundant near Clear Lake, in California; Inferno, 
Humboldt County, and Rabbit Hole Mines, Nevada; near 
Evanston, Wyoming; in Utah, Idaho, ete. 

The native sulphur of commerce is brought largely from 
Sicily, where it occurs in beds along the central part of the 
south coast and to some distance inland. It undergoes 
rough purification by fusion before exportation, which 
separates the earth and clay with which it occurs. 

Sulphur when cooled from fusion, or above 232° F., crys- 
tallizes in odligue rhombic prisms. When poured into 
water at a temperature above 300° F. it acquires the con- 
sistency of soft wax, and is used to take impressions of 
gems, medals, etc., which harden as the sulphur cools. 
The uses of sulphur for gunpowder, bleaching, the manu- 
facture of sulphuric acid (which is the chief use), and also 
in medicines, are well known. Sulphur occurs in various 
ores as sulphides and sulphates, Among the sulphides are 
pyrite, marcasite and pyrrhotite, iron sulphides; galena, a 
lead sulphide, the common ore of lead; chalcopyrite, or 
yellow copper-ore, a copper and iron sulphide; cinnabar, a 
mercury sulphide; argenti/e, a silver sulphide, etc. 


Sulphuric and Sulphurous Acids. 


Sulphuric acid is occasionally met with around volca- 
noes, and it is also formed from the decomposition of hy- 
drogen sulphide about sulphur springs. 


108 DESCRIPTIONS OF MINERALS. 


It is intensely acid. Composition, Sulphur trioxide 
(SO,) 81.6, water 18.4 = 100, it being chemically hydrogen 
sulphate. Occurs in the waters of Rio Vinagre, South 
America; in Java; in Genesee Co., N. Y., at Tuscarora; 
St. Davids, and elsewhere, Canada West. 

Manufactured from sulphur, and also from the common 
sulphides, especially pyrite. 

Sulphurous acid, or sulphur dioxide (SO,), is produced 
when sulphur burns, and causes the odor perceived during 
the combustion of mineral coal. Common about active 
volcanoes. It destroys life and extinguishes combustion. 
Composition, Sulphur 50.00, oxygen 50.00. 


Native Tellurium. 


Rhombohedral; R A R= 86° 57’. Occurs sometimes 
in six-sided prisms with perfect dateral cleavage; but is 
commonly granular massive. Color and streak tin-white. . 
Brittle. H. = 2-2.5. G. = 6.1-6.3. | 

Sometimes contains a little iron, and also a trace of 
gold. In an open tube, B.B. yields a white inodorous sub- 
limate, which may be fused to colorless transparent drops; 
and on charcoal fuses and volatilizes, tinging the flame 
green, and covering the charcoal with white tellurium di- 
oxide. 

Obs. Occurs in Hungary and Transylvania; also,-Boul- 
der Co., Colorado, at the Red Cloud Mine; in Magnolia 
District at the Keystone, Dun River, and other mines; in 
the Ballerat District at Smuggler Mine; in Central Dis- 
trict at the John Jay Mine, where masses of 25 pounds 
weight are reported to have been found. Jioniée is an im- 
pure variety from Mountain Lion Mine. 

Tellurium is also a constituent of ores of gold, silver, mercury, 
bismuth, and lead, forming with the metals tellurides (pp. 102, 116, 
117, 118, 129, 147); petzite and sylvanite (p. 118) are the most abun- 
dant, and large quantities—from Boulder Co., Colorado, chiefly—are 
smelted for gold and silver at Denver. Tellurium is not used in the 
arts. 

Tellurite (Tellurous acid), TeO:. The Keystone, Smuggler, and 
John Jay Mines; especially the last, where it is in minute white or 
yellowish crystals having one eminent cleavage. 


Molybdenite.—Molybdenum Sulphide. 


In hexagonal plates, or masses, thin foliated like graph- 
ite, and resembling that mineral H. =1-15. G. = 


MINERALS CONSISTING OF THE ACIDIC ELEMENTS. 109 


4,45-4.8. Color pure lead-gray; streak the same, slightly 
inclined to green. Thin lamine very flexible; not elastic. 
Leaves a trace on paper, like graphite, but its color is 
slightly different, being bluish-gray. 

Composition, MoS, = Sulphur 41.0, molybdenum 59.0 
= 100. B.B. infusible; but when heated on charcoal, 
sulphur fumes are given off, which are deposited on the 
coal. Dissolves in nitric acid, excepting a gray residue. 

Diff. Resembles graphite, but differs in its paler color 
and streak, and also in giving fumes of sulphur when 
heated, as well as by its solubility in nitric acid. 

Obs. Occurs in granite, gneiss, mica schist, and allied 
rocks; also in granular limestone. Found in Sweden; at 
Arendal in Norway; in Saxony; Bohemia; Caldbeck Fell 
in Cumberland; and in the Cornish mines. 

In the U. 8. occurs at Blue Hill Bay, Camdage Farm, 
Brunswick, and Bowdoinham, Me.; at Westmoreland, 
Landaff, and Franconia, N. H.; at Shutesbury and Brim- 
field, Mass.; at Haddam and Saybrook, Ct.; near Warwick, 
N. Y.; near Franklin Furnace, N. J. 

Molybdenum does not occur native. Yellow oxide is an 
occasional result of its alteration. Occurs combined with 
lead as a molybdate (page 151), which is the only native 
salt containing it. Named from the Greek molubdaina, 
meaning mass of lead, in allusion to the resemblance of 
molybdenite to graphite. 

Tungstiie (Tungstic ochre). A yellow powder or incrustation oc- 
curring with wolfram, and a result of its decomposition. Occasion- 
ally observed at Lane’s Mine, Monroe, Ct. Meymacite ; hydrous W Qs. 

Besides this oxide there are the native compounds, iron tungstate 
or wolfram (p. 200), manganese tungstate (p. 200), lead tungstate (p. 
66), and calcium tungstate (p. 232). Tungsten also occurs sparingly 


in some ores of niobium, as in certain varieties of the minerals 
pyrochlore, columbite, and yttro-columbite. 


2, BORON GROUP. 


In Boron, as in the Sulphur group, the most prominent 
oxide is a trioxide. 


Sassolite.—Boracic Acid. Sassolin. 


Occurs in small scales, white or yellowish. Feel smooth 
and unctuous. ‘Taste acidulous and a little saline and bit- 
ter. G. = 1.48. Composition, H,O,Bo, = Boron triox- 
ide 56.4, water 43.6. It is strictly hydrogen borate. 


110 DESCRIPTIONS OF MINERALS. 


Fuses easily in the flame of a candle, tinging the flame 
at first green. 

Found at the crater of Vulcano, and also at Sasso in 
Italy, whence it was called Sassolin. The hot vapors of 
the lagoons of Tuscany afford it in large quantities. ‘The 
vapors are made to pass through water, which condenses 
them; and the water is then evaporated by the steam of 
the springs, and boracic acid obtained in large crystalline 
flakes. It still requires purification, as the best thus pro- 
cured contains but 50 per cent of the pure acid. Occurs 
also in the waters of Lick Springs, Tehama Co., and Borax 
Lake, Lake Co., California, where it was first observed, 
through their evaporation, by Dr. J. A. Veatch, in 1856. 
It has since been obtained from the waters of Mono, 
Owens, and other lakes. It exists sparingly in the waters 
of the ocean. But in all these waters, it is probably in 
combination. . 


Boron occurs usually in the condition of magnesium, calcium, and 
sodium borates (pp. 225, 281, 246); and rarely as an iron borate (p. 
182), or ammonium borate (p. 231). It also occurs in the silicates, 
tourmaline, danburite, axinite, and datolite, in which it is easily de- 
tected by the blowpipe reaction (p. 99). The borax of commerce 
(hydrous sodium borate) is derived mostly from native borax (p. 99), 
but also from the sodium-calcium borate (ulexite) and to some extent 
from sassolin. 


3. THE ARSENIC GROUP. 


The elements of the Arsenic group occurring among 
minerals are arsenic, antimony, bismuth, phosphorus, 
nitrogen, vanadium, tantalum, niobium. Of these, ar- 
senic, antimony, and bismuth occur native, and as sul- 
phides; also, in combination with other metals, constituting 
arsenides, antimonides, bismutides; and, along with sul- 
phur also, making sulpharsenites, sulphantimonites, sulph- 
bismutites. In addition, they all, excepting bismuth, en- 
ter into the constitution of a series of native ternary oxygen 
compounds, called, severally, arsenates, antimonates, phos- 
phates, nitrates, vanadates, tantalates, niobates. 

The chief oxide has the general formula R,0,,. 


Native Arsenic. 


Rhombohedral. R A R= 85° 41’. Cleavage basal, im- 
perfect. Also massive, columnar, or granular, 


MINERALS CONSISTING OF THE ACIDIO ELEMENTS. 111 


Color and streak tin-white, but usually dark grayish from 
tarnish. Brittle. H.=3°5. G. = 5°65-5°95. 

B.B. volatilizes readily before fusing, with the odor of 
garlic; burns with a pale bluish flame when heated just 
below redness. 

Obs. Occurs with silver and lead ores. Found in con- 
siderable quantities at the silver mines of Freiberg and 
Schneeberg; in Bohemia; the Hartz; at Kapnik in Upper 
Hungary; in Siberia in large masses, and elsewhere. 

In the U. States observed sparingly at Haverhill and 
Jackson, N. H.; at Greenwood, Me. 


Orpiment.— Yellow Arsenic Sulphide. 


Orthorhombic. Cleavage highly perfect in one direction. 
In foliated masses, and sometimes in prismatic crystals. 
Color and streak fine yellow. Lustre brilliant pearly, or 
metallic pearly, on the face of cleavage. Subtransparent 
to translucent; sectilee H.—1°5-2. G. =3°4-3°'5. 

Composition. As,S,= Sulphur 39°0, arsenic 61°0. 
Wholly evaporates before the blowpipe with an alliaceous 
odor, and on charcoal burns with a blue flame. 

From Hungary, Koordistan in Turkey in Asia, China, 
and South America. Occurs at Edenville, N. Y., as a yel- 
low powder, resulting from the decomposition of arsenical 
iron; Coyote Dist., Iron Co., Utah. 

Realgar. The arsenic sulphide As§. Color fine clear red, aurora- 
red to orange, transparent or translucent; H.= 1°5-2; G.= 3°35-3°65; 
Composition, AsS—=Sulphur 29°9, arsenic 70°1—100. B.B. like 
the preceding. Hungary, Bohemia, Saxony, the Hartz, Switzerland, 
and Koordistan in Asiatic Turkey. Has been observed in the lavas 
of Vesuvius. 

Realgar is one of the ingredients of white Indian fire, often used as 
a signal light. Orpiment is a coloring ingredient in the pigment called 
king’s yellow, in which it is mixed with arsenous acid. 


Arsenolite.— White Arsenic. Arsenous Acid. 


Isometric. In minute capillary crystals, and botryoidal 
or stalactitic. Color white. Soluble; taste astringent, 
sweetish, H.=1°5. G. = 3°%. 

Composition. As,O, = Arsenic 75°8, oxygen 24°2 = 100. 

The common arsenic of the shops. Found sparingly na- 
tive, accompanying ores of silver, lead, and arsenic, in the 
Hartz, Bohemia, and elsewhere. A well-known poison. 
Bld is the same compound in orthorhombic forms; from Por- 

gal. j 


112 DESCRIPTIONS OF MINERALS. 


General Remarks.—Arsenic is obtained for commerce chiefly from 
arsenopyrite (or mispickel), an iron sulph-arsenide, and from the nickel 
and cobalt arsenides, by first roasting off the sulphur, and then con- 
densing the arsenic, in the state of As: O; (“‘arsenous acid”) in large 
chambers. Arsenopyrite is used for making the oxide at the Deloro 
mine in Ontario, Canada, where 200 tons were produced in 1884. To 
obtain the material pure it is usually sublimed again. In Devon and 
Cornwall the arsenical ores occur with the tin ore, and a large amount 
of white arsenic is made. ‘The metal arsenic forms a small part of 
some alloys; the most important is that with lead for shot-making. 
3,693,325 pounds of white arsenic were imported into the U. States 
in 1884, and 5,207,553 pounds in 1883. 


Native Antimony. 


Rhombohedral; RA & = 87° 35’. Usually massive, with 
a very distinct lamellar structure; sometimes granular. 
Color and streak tin-white. Brittle. H. = 3-3. G.= 
6°6-6°75. 

Composition. Pure antimony, often with a little silver, 
iron, or arsenic. B.B. on charcoal fuses easily and passes 
off in white fumes. 

Obs. Occurs in veins of silver and other ores in Dauphiny; 
Bohemia; Sweden; the Hartz; Mexico; New Brunswick. 


Stibnite.—Gray Antimony. Antimony Sulphide. iy, 
Orthorhombic; 7A J = 90° 26’. Inright rhombic prisms, - 


with striated lateral faces. Cleavage in the direction of : 


the shorter diagonal, highly perfect. Com- 
monly divergent columnar or fibrous. Some- 
times massive granular. 

Color and streak lead-gray; liable to tarnish. 
Lustre shining. Brittle; but thin lamine a 
little flexible. - Somewhat sectilee H. =2. 
G. = 4°5-4°62, ; 

Composition. Sb,S, = Sulphur 28°2, anti- 
mony 71°8. Fuses readily in the flame of a 
candle. B.B. on charcoal it is absorbed, giy- 
ing off white fumes and a sulphur odor. 

| Diff. Distinguished by its extreme fusibility 
and its vaporizing before the blowpipe. 

Obs. In veins with ores of silver, lead, zinc, or iron, and 
often associated with barite, spathic iron, or quartz. Oc- 
curs at Felsdbanya and Schemnitz in Hungary; Wolfsberg 
in the Hartz; Briunsdorf near Freiberg; in Auvergne; 
Cornwall; Spain; Portugal; Tuscany, Italy; Borneo; Shi- 





MINERALS CONSISTING OF THE ACIDIC ELEMENTS. 113 


koku, 8. Japan, in magnificent crystals; N. 8. Wales and 
Victoria, Australia. 

In the U. States, sparingly at Carmel, Me., Lyme, N. H., 
and at ‘‘ Soldier’s Delight,” Md.; abundant in San Emidio 
Cafion, Kern Co., Cal.; also in San Bernardino, Inyo, 
Mono, Lake, Tulare, and Monterey Cos., Cal.; in Relief 
district, Humboldt Co., Ney.; in the mines of Aurora, Es- 
meralda Co., Ney.; also 12 miles south of Battle Mountain, 
Ney.; in Utah, in Iron Co., on Coyote creek, abundant. 
Also worked in N. Brunswick, 20 miles west of Fredericton; 
in Rawdon township, Hants Co., N. Scotia. 

Affords the most of the antimony of commerce. By sim- 
ple fusion, the crude antimony of the shops is obtained, 
from which pure antimony and its pharmaceutical prepara- 
tions are made. Antimony constitutes 17.20 per cent. of 
type-metal, 10 to 16 per cent. of Britannia metal, 8.3 per 
cent. of Babbitt metal, and about 7 of pewter. 

Allemontite. Arsenical antimony, Sb2As;. Allcmont; Bohemia; 
the Hartz. 

Valentinite. White antimony in white, grayish, or reddish rectan- 
gular crystals, with perfect cleavage, affording a rhombic prism of 
186° 58’. Also in tabular masses, and columnar and granular, H.= 
2°5-8. G.= 5°57. Lustre adamantine to pearly. Composition, Sba 
‘O; = Oxygen 16°44, antimony 83°56= 100. Bohemia; Hungary; 
. Saxony; Dauphiny; Sonora, Mexico. 

Senarmonite. Same as Valenvtinite, but isometric. 

Kermesite or Red antimony. An antimony oxide and sulphide, in 
red tufts of capillary crystals; lustre adamantine. Hungary, Dau- 
phiny, Saxony, the Hartz. 

Cervantite. Antimony oxide, Sbz O,, resulting from the decompo- 
sition of stibnite. 

Livingstonite. Like stibnite, but contains 14 per cent. of mercury 
and has a ved streak. Huitzuco and Guadalcazar, Mexico. 


Native Bismuth. 


Rhombohedral; RA R= 87° 40’. Cleavage rhombo- 
hedral, perfect. Generally massive, with distinct cleavage; 
sometimes granular. 

Color and streak silver white, with a slight tinge of red. 
Subject to tarnish. Brittle when cold, but somewhat mal- 
leable when heated. H. = 2-2°5. G.=9°7-9°8. Fuses 
at a temperature of 476° F. 

Composition. Pure bismuth, with sometimes a trace of 
arsenic, sulphur, or tellurium. 3B.B. on charcoal vaporizes, 
and leaves a yellow coating on the coal, paler on cooling. 

Obs. Abundant with ores of silver and cobalt in Saxony 

8 


114 DESCRIPTIONS OF MINERALS. 


and Bohemia; also in Cornwall and Cumberland, England; 
in Norway, Sweden, Chili, and Bolivia; at the Balhannah 
mine, in 8. Australia, with copper ore and gold. At 
Schneeberg, it forms arborescent delineations in brown 
asper. 

; In the U. States, found at Lane’s and Booth’s mine, 
Monroe, Ct., with tungsten, galenite, and pyrite; at Brew- 
er’s mine, in Chesterfield district, 8. C.; in Colorado; 12 
miles west of Beaver City, Utah. 

Bismuthinite. A bismuth sulphide, Bi: 83, in acicular crystals of a 
lead-gray color; also massive. Five miles N. of Golden, Col.; in 
Beaver Co., Utah ; and elsewhere. 

Guanajuatite. A bismuth selenide, called also frenzelite. Silaontte, 
from the same locality, is a mixture. Guanajuato, Mexico. 


Tetradymite.—Bismuth Telluride. 


Hexagonal; Rk A R = 81° 2’. Crystals often tabular, with 
avery perfect basal cleavage. Also massive, and foliated 
or granular. Lamine flexible. Lustre splendent metallic. 
Color pale steel-gray, a little sectilee H.=15—2. G.= 
7°2—7'9. Soils paper. 

Composition. Consists of bismuth and tellurium, with 
sometimes sulphur and selenium. Affords for the most 
part the formula Bi, (Te, $),. A variety from Dahlonega, 
Ga., gave Tellurium 48:1, bismuth 51°9=Bi,Te,; G.= 
7°642. Josette is a bismuth telluride from Brazil, in which 
half the bismuth is replaced by sulphur; Wehriite is an- 
other containing sulphur, from Deutsch Pilsen, Hungary, 
having G.=8°44. 

Obs. Found with gold in Virginia, N. Carolina, and 
Ga.; Highland, Montana; Red Cloud Mine, Col.; Mont- 
gomery Mine, Arizona. 

Bismite (Bismuth ochre). An impure oxide; grayish to greenish 
and yellowish white ; massive or earthy. Found with native bismuth. 
Bolivite is a related mineral. 

Daubréite. A bismuth oxychloride. Bolivia. 

Bismutite. Bismuth carbonate; pale yellow to green, G.=7—7'5. 
Found with other bismuth ores. Waltherite and Bismutospherite be- 
long here. Montanite is bismuth tellurate; Montana; N. Car. 

Pucherite. Bismuth vanadate; orthorhombic; reddish brown. 
Schnecberg, Saxony. Afelestite, Rhagite, bismuth arsenate. 

Taznite. Supposed to be a bismuth arsenio-antimonate. Peru. 

For the sulpho-bismuthides, sce pp. 00, 00; and for a silicate, p. 0. 

General Remarks.—The metal bismuth is obtained mostly from na- 
tive bismuth, and the most valuable mines are in Saxony, Hungary, 
Baden, Cornwall, and Australia. Besides the above ores, there are 


* 
2] 


MINERALS CONSISTING OF THE ACIDIC ELEMENTS. 115 


also others in which the metal is combined with silver, lead, and 
nickel (pp. 184, 183). 


4, CARBON GROUP, 


The Carbon group in chemistry comprises carbon and 
silicon, in which the formula for the most prominent oxide 
is RO,. Only carbon occurs native. 

Carbon occurs crystallized in the diamond and graphite; 
as oxides, in carbon oxide, and carbon dioxide (ordinarily 
called carbonic acid); combined with hydrogen, or hydrogen 
and oxygen, in bitumen, mineral oils, amber, and a num- 
ber of native mineral resins, and mineral wax; and as the 
chief constituent of mineral coal, in which it is combined 
with more or less of hydrogen and oxygen and usually some 
nitrogen. 


Diamond, 


Isometric. In octahedrons, dodecahedrons and more 
complex forms ; faces often curved. Cleavage octahedral ; 
perfect. 


Q 


Color white, or colorless; also yellowish, red, orange, 
green, blue, brown or black. Lustre adamantine. Trans- 
parent; translucent when dark-colored. H.=10. G.= 
3°48 —3°55. 

Composition. Pure carbon. Burns and is consumed at a 
high temperature, producing carbonic-acid gas. Exhibits 
vitreous electricity when rubbed. Some specimens exposed 
to the sun for a while give out light when carried to a dark 
place. Strongly refracts and disperses light. 

Diff. Distinguished by the hardness; brilliant reflection 
of light and adamantine lustre; vitreous electricity when 
rubbed, which is not afforded by other gems unless they are 





116 DESCRIPTIONS OF MINERALS. 


polished ; and, to the practised ear, by means of the sound 
when rubbed together. 

Obs. Coarse diamonds, unfit for jewelry, are called dort, 
and the kind in black pebbles, or masses, from Brazil, car- 
bonado. ‘The latter occur sometimes in pieces 1000 carats 
in weight; they have G.=3 to 3°42. Another kind is much 
like anthracite, G.=1°66, although as hard as diamond 
crystals; it is in globules or mammillary masses, often partly 
made up of concentric layers. 

Diamonds occur in India, in the district between Golconda 
and Masulipatam, and near Parma, in Bundelcund, where 
some of the largest have been found; alsoon the Mahanud- 
dy, in Ellore. In Borneo, they are obtained on the west 
side of the Ratoos Mountain, with gold and platina. ‘The 
Brazilian mines were first discovered in 1728, in the district 
of Serra do Frio, to the north of Rio de Janeiro; the most 
celebrated are on the river Jequitinhonha, which is called 
the Diamond River, and the Rio Pardo; seventy to seventy- 
five thousand carats are exported annually from these re- 
gions. In the Urals of Russia they had not been detected 
till July, 1829, when Humboldt and Rose were on their 
journey to Siberia. ‘The river Gunil, in the province of 
Constantine, in Africa, is reported to have afforded some 
diamonds. 

In South Africa, where they were first discovered in 1867, 
they occur in the gravel of the Vaal River and in the 
Orange River country. In Australia, on the Macquarie, 
and elsewhere. 

In the United States, the diamond has been met with in 
Rutherford, Lincoln, Mecklenburg, Franklin, and other 
counties, N. C.; Hall Co., Ga.; Manchester, opposite Rich- 
mond, Va., a crystal weighing 24? carats before cutting, 
and nearly half that after cutting; also in Cherokee Flat, 
and other places in Butte Co., Forest Hill in El Dorado 
Co. (one weighing nearly 13 carats), Fiddletown in Amador 
Co., San Juan Co. in Colorado; in Nevada Co., Cal.; and 
with platinum on the coast of Southern Oregon; and one 
fine stone of 2ths carat, near San Francisco. It has been 
reported from Idaho, Arizona, Montana; also from the 
drift in Waukesha Co., Wis., one of 15 carats. 

The original rock in Brazil appears to be either a lami- 
nated quartzyte (itacolumyte), or a ferruginous quartzose 
conglomerate. ‘The itacolumyte occurs in the Urals, and 


MINERALS CONSISTING OF THE ACIDIC ELEMENTS. 117 


diamonds have been found in it; and it is also abundant 
in Georgia and North Carolina. According to Genth, the 
auriferous sands in N. Carolina, affording the diamond with 
zircons, monazite, etc., are the débris of gneiss and mica 
schist, and some graphite is always present. In India, 
the rock is a quartzose conglomerate. The origin of the 
diamond has been a subject of speculation, and it is the 
prevalent opinion that the carbon, like that of coal, much 
graphite, and mineral oil, is of vegetable or animal origin. 
Some crystals have been found with black uncrystallized 
ee or seams within, looking like coal; and this fact 
as been supposed to indicate such an origin. 

Diamonds, with few exceptions, are obtained from allu- 
vial washings. In Brazil, the sands and pebbles of the 
diamond rivers and brooks (the waters of which are drawn 
off in the dry season to allow of the work) are collected and 
washed under a shed, by a stream of water passing through 
a succession of boxes. A washer stands by each box, and 
inspectors are stationed at intervals. 

Diamonds are valued according to their color, transpa- 
rency, and size. ‘The rose diamond is more valuable than 
the pure white, owing to the great beauty of its color and 
its rarity. The green diamond is much esteemed on ac- 
count of its color. The blue is prized only for its rarity, as 
the color is seldom pure. The black diamond, which is 
uncommonly rare and without beauty, is highly prized by 
collectors. ‘The brown, gray, and yellow varieties are of 
much less value than the pure white or limpid diamond. 

The largest diamond on record (doubtful) is that men- 
tioned by ‘Tavernier as in the possession of the Great Mogul. 
It weighed originally 900 carats, or 2769°3 grains, was re- 
duced by cutting to 861 grains, had the form and size of half 
of a hen’s egg, and is said to have been found in 1550, in 
the mine of Colone. The diamond which formed the eye 
of a Braminican idol, and was purchased by the Empress 
Catherine II. of Russia from a French grenadier who had 
stolen it, weighs 194? carats, and is as large as a pigeon’s 
egg. The Austrian crown has a diamond weighing 139} 
carats. The Pitt or Regent diamond is of less size, it 
weighing but 136°25 carats, or 419} grains; but on account 
of its unblemished transparency and color it is considered 
the most splendid of Indian diamonds. It was sold to the 
Duke of Orleans by Mr. Pitt, an English gentleman, who 


118 DESCRIPTIONS OF MINERALS. 


was governor of Bencoolen, in Sumatra, for £130,000. It is 
cut in the form of a brilliant, and is estimated at £125,000. 
The Rajah of Mattan has in his possession a diamond from 
Borneo, weighing 367 carats. The Koh-i-noor, on its arrival 
in England, weighed 186°016 carats.* It is said by ‘Taver- 
nier to have originally weighed 7874 carats. It has since 
been recut and reduced one third in weight. 

In the Dresden 'Treasury there is an emerald-green dia- 
mond weighing 314 carats. The Hope diamond, weighing 
44} carats, has a beautiful sapphire-blue color. 

The diamonds of Brazil are seldom large. Maure men- 
tions one of 120 carats, but they rarely exceed 18 or 20. 
One weighing 2543 carats, called the “‘ Star of the South,” 
was found in 1854. | 

Of South African diamonds, the ‘‘ Schreiner” weighed, 
in its rough state, 308 carats; and the ‘‘ Stewart,” which 
has a light straw color, 288°35 carats; and one of 475 carats 
was reported in 1885 as about to be cut at Amsterdam. 
The diamonds of South Africa are mostly ‘‘ off color”; about 
10 per cent. are of first quality; 15, 2d; 20, 3d; and 55 per 
cent. are dort (W. J. Morton). The ‘‘ Star of South Africa,” 
of pure water, weighed 83°5 carats. Some crystals crack 
to pieces after being exposed to the air awhile. 

The diamond is cut by taking advantage of its cleavage, 
and also by abrasion with its own powder. The flaws are 
sometimes removed by cleaving it. Afterwards the crystal 
is fixed to the end of a stick of soft solder when the solder 
is in a half-melted state, leaving the part projecting which 
is to be cut. A circular plate of soft iron is then charged 
with the powder of the diamond, and this, by its revolution, 
grinds and polishes the stone. By changing the position, 
other facets are added in succession till the required form 
is obtained. Diamonds were first cut in Europe, in 1456, 
by Louis Berghem, a citizen of Bruges; but in China and 
India the art of cutting appears to have been known at a 
very early period. 

By the above process, diamonds are cut into brilliant, rose, 
and ¢ab/e diamonds. The brilliant has a crown or upper 
part, consisting of a large central eight-sided facet, and a 


* A carat is a conventional weight. In England it equals 3174 grains troy. 
Schrauf makes it vary.in Europe from 197°20 mgr. to 206°13. and in London 205°409., 
The term carat is derived from the name of a bean in Africa, which, in a dried 
state, has long been used in that country for weighing gold. These beans were 
early carried to India, and were employed there for weighing diamonds. 


MINERALS CONSISTING OF THE ACIDIC ELEMENTS. 119 


series of facets around it; and a collet, or lower part, of py- 
ramidal shape, consisting of a series of facets, with a smaller 
series near the base of the crown. ‘The depth of a brilliant 
is nearly equal to its breadth, and it therefore requires a 
thick stone. Thinner stones, in proportion to the breadth, 
are cut into rose and table diamonds. ‘The surface of the 
rose diamond consists of a central eight-sided facet of small 
size, eight triangles, one corresponding to each side of the 
table, eight trapeziums next, and then a series of sixteen 
triangles. The collet side consists of a minute central octa- 
gon, surrounded by eight trapeziums, corresponding to the 
angles of the octagon, each of which trapeziums is subdi- 
vided by a salient angle into one irregular pentagon and 
two triangles. The ¢ad/e is the least beautiful mode of cut- 
ting, and is used for such fragments as are quite thin in 
proportion to the breadth. It hasa square central facet, 
surrounded by two or more series of four-sided facets, cor- 
responding to the sides of the square. 

Diamonds have also been cut with figures upon them. 
As early as 1500, Charadossa cut the figure of one of the 
Fathers of the church on a diamond, for Pope Julius II. 

Diamonds are employed for cutting glass; and for this 
purpose only the natural edges of crystals can be used, and 
those with curved faces are much the best. Diamond dust 
is used to charge metal plates of various kinds for jewellers, 
lapidaries, and others. Drills are made of small splinters 
of bort, and used for drilling other gems, and also for 
piercing holes in artificial teeth and vitreous substances 
generally; and others of iron set with a few diamonds, for 
drilling rocks. 


Graphite.—Plumbago. 


Hexagonal. Sometimes in six-sided prisms or tables with 
a transversely foliated structure. Usually foliated, and 
massive; also granular and compact. 

Lustre metallic, and color iron-black to dark steel-gray. 
Thin lamine flexible. H. =1-2. G. = 2:25-2:27. Soils 
paper, and feels greasy. 

Composition. Commonly 95 to 99 per cent. of carbon. 
B.B. infusible, both alone and with reagents; not acted 
upon by acids. 

Diff. Resembles molybdenite, but differs in being unaf- 
fected by the blowpipe and acids. The same characters 


120 DESCRIPTIONS OF MINERALS. 


distinguish the granular varieties from any metallic ores 
they resemble. 

Obs. Graphite (called also dlack lead) is found in crys- 
talline rocks, in veins, and as a constituent of mica schist 
or gneiss; also in crystalline limestone; in argillyte, and 
occasionally in sandstone. In Rhode Island and at Worces- 
ter, Mass., it occurs in beds of the coal formation. Its 
principal English locality at Borrowdale, in Cumberland, 
is now nearly exhausted. 

In the U. States it is worked at Roger’s Rock, near Ti- 
conderoga; less abundant in gneiss at Sturbridge, Mass.; 
North Brookfield, Brimfield, and Hinsdale, Mass.; Corn- 
wall and Ashford, Ct.; Brandon, Vt.; Rossie, in St. Law- 
rence Co.; near Amity, Orange Co., N. Y.; Greenville, 
N. C.; near Attleboro, in Bucks County, Pa.; Wake, 
N. C.; on Tyger River, and at Spartanburg, near the Cow- 
pens Furnace, and Greenville, 8. C.; Albany Co., Wyom- 
ing; Pitkin, Gunnison Co., Col.; Black Hills, Dak.; Sonora 
Mine, Tuolumne Co., Cal.; N. Mexico; also of excellent 
quality in Canada, in Buckingham, Fitzroy, and Grenville, 
but not worked in 1884. 

Ceylon, Bavaria, and Siberia afford most of the foreign 
graphite. About 17,348,000 pounds were imported into 
the U. States in 1883. In the same year the yield of the 
U. States was only 575,000 pounds, and all was from the 
Ticonderoga mine; in 1884 this mine was not worked. 

For the manufacture of the best pencils the granular 
graphite was thought necessary, and hence the former great 
value of the Borrowdale mine, where the texture was pecu- 
harly fine and firm. But now the graphite is ground up, 
and then compressed under heavy pressure, and thus the 
fine texture and firmness required may be obtained with 
any pure graphite, though some cement is generally used; 
fine clay is added to make the harder pencils. 

Graphite is extensively employed for diminishing the 
friction of machinery; also for the manufacture of crucibles 
and furnaces; in electrotyping; as a polish for iron stoves 
and railings. Lor crucibles it is mixed with half its weight 
of clay. Price, 1-10 dollars per cwt., according to quality. 


Carbonic Acid. 


Carbonic acid—carbon dioxide of chemistry—is the gas 
that gives briskness to the Saratoga and many other mineral 





MINERALS CONSISTING OF THE ACIDIC ELEMENTS...121 


waters, and to artificial ‘soda water.” Its taste is slightly 
pungent. It extinguishes combustion and destroys life. 

Composition. CO, = Oxygen 72°35, carbon 27°65 = 100. ~ 

This gas is contained in the atmosphere, constituting 
about 3 parts, by volume, in 10,000 parts; and it is present 
in minute quantities in the waters of the ocean and land. 
It is given out by animals in respiration, and is one of the 
results of animal and vegetable decomposition; and from 
this source the waters derive much of their carbonic acid. 
This gas is the choke-damp of mines, where it is often the 
occasion of the destruction of life. It is often present also 
in wells. 

Carbon dioxide (or carbonic acid) is given out by lime- 
stone (or calcium carbonate) when it is heated; and quick- 
lime is limestone from which CO, has been expelled by heat, 
a process carried on usually ina limekiln. It is expelled 
also by sulphuric acid, with the formation of gypsum (a 
hydrous calcium sulphate), or anhydrite (an anhydrous cal- 
cium sulphate), and this is one source of gypsum beds in 
rocks of different ages. These processes are often carried. 
on in volcanoes, and hence carbonic-acid gas is common in 
some volcanic regions. The Grotto del Cane (Dog Cave) 
at the Solfatara near Naples is a small cavern filled to the 
level of the entrance with this gas, It is a common amuse- 
ment for the traveller to witness its effect upon a dog kept 
for that purpose. He is held in the gas awhile and is then 
thrown out apparently lifeless; in afew minutes he recovers 
himself, picks up his reward, a bit of meat, and runs off as 
lively as ever. If continued in the carbonic-acid gas a 
short time longer, life would have been extinct. 

Carbonic acid, under high pressure, becomes a liquid, 
and, with pressure and cold, a white snowlike solid. In 
the liquid state it is often found in microscopic globules in 
the interior of crystallized quartz, topaz, and some other 
minerals; and when this is true, calcite (calcium carbonate) 
is often present in the same or an adjoining rock. 

Besides the calcium carbonate in nature, there are also carbonates 
of ammonium, sodium, barium, strontium, magnesium, iron, manga- 


nese, zinc, copper, lead, nickel, cobalt, bismuth. uranium, cerium, 
and Janthanum. 


122 DESCRIPTIONS OF MINERALS. 


II. MINERALS CONSISTING OF THE BASIC ELE- 
MENTS WITH OR WITHOUT ACIDIC—THE 
SILICATES EXCLUDED. 


I. GOLD. 


Gold occurs mostly native, being either pure, or alloyed 
with silver and other metals. It is occasionally found min- 
eralized by tellurium, making part of the valuable minerals 
Sylvanite, Nagyagite, and Petzite. 


Native Gold. 


Isometric. In octahedrons, dodecahedrons; without 
cleavage. Also in arborescent forms, consisting of strings 
of crystals, filiform, reticulated; also in grains, thin laminee 
or scales, and in masses. 

Color various shades of gold-yellow, paler when alloyed 
with silver, and occasionally nearly silver-white. Emi- 
nently ductile and malleable. H. = 25-3. G. when pure 
(native) 19-19°30, varying to 15 and 12 according to the 
metals alloyed with the gold. Fuses at 2016° F. (1102° 


“Composition. Native gold is usually alloyed with silver. 
The finest native gold from Russia yielded gold 98°96, 





silver 0°16, copper 0°35, iron 0°05; G. = 19:099. A gold 
from Marmato afforded only 73°45 per cent. of gold, with 
26°48 per cent. of silver; G. = 12°666. ‘This last is in the 
proportion of 3 of gold to 2 of silver. The following pro- 
portions also have been observed: 3} to 2; 5 to 2; 3 tol; 


MINERALS CONSISTING OF THE BASIC ELEMENTS. 123 


4to1, and this the most common; 6 to 1 is also of frequent 
occurrence. Average of California native gold is 88 per 
cent. gold, and the range mostly between 87 and 89; the 
range of the Canadian, mostly between 85 and 90; of Aus- 
tralian, between 90 and 96 per cent., and the average 934. 
The Chilian gold afforded Domeyko 84 to 96 per cent. of 
gold, and 15 to 3 per cent. of silver. ‘The more argentif- 
erous gold has been called Hectrum; the atomic proportion 
of 1:1 between the gold and silver corresponds to 35°5 
per cent. of silver, and that of 2 : 1, to 21°6 per cent. 

Copper is occasionally found in alloy with gold, and some- 
times also iron, bismuth, palladium, and rhodium. A 
rhodium-gold from Mexico gave the specific gravity 15°5- 
16°8, and contained 34 to 43 per cent. of rhodium. A bis- 
muth gold has been called Maldonite. 

Diff. Tron and copper pyrites are often mistaken for gold 
by those inexperienced in ores; but these are brittle min- 
erals, while gold may‘be cut in slices, and flattens under a 
hammer. Pyrite is too hard to yield at all to a knife, and 
copper pyrites (chalcopyrite) affords a dull greenish pow- 
der. Moreover pyrite gives off sulphur when strongly 
heated, while gold melts without odor. 

Obs. Mostly confined to veins of quartz, intersecting or 
interlaminated with subecrystalline slaty or schistose rocks, 
especially hydromica and chloritic schists; occurs spar- 
ingly in similar or other veins in granite, gneiss, or mica 
schist; sometimes occurs in slate rocks adjoining the veins. 
Found in traces, according to J. J. Stevenson, in the tra- 
chytes of Colorado, and in Silurian and Carboniferous 
quartzites. Gold also exists in sea-water—nearly 1 grain 
to a ton of water. 

The quartz is frequently cellular for a considerable dis- 
tance from the surface owing to the alteration and removal 
of pyrite, galena, or other metallic ores that may be accom- 
paniments of the gold, and the cavities are usually rusty 
with oxide of iron, and sometimes contain particles of sul- 
phur left by the decomposing pyrite, and also strings or 
lamine of gold derived from the decomposed minerals. 
The rock in this cavernous state is rather easily quarried 
out; but deep below, where the minerals are not removed 
by decomposition, mining is far more difficult. ‘The aurif- 
erous quartz often contains no gold that the naked eye or 
eyen a pocket lens can detect. The pyrite of a gold region 


124 DESCRIPTIONS OF MINERALS. 


is often so auriferous as to make a very valuable gold ore, 
and this is true also of galenite. 

While quartz veins are to a large extent the original re- 
positories of native gold, a large part of the gold of aurif- 
erous regions comes from the sand and gravel beds, in 
which it occurs in flattened grains, and sometimes in lumps 
or nuggets. By different methods—erosion by running 
waters, movements of glaciers, natural decomposition, and 





been extensively reduced to earth and stones, and this loose 
material has been distributed along the river-courses, mak- 
ing vast alluvial or diluvial gravelly formations. From 
these gravels the gold i is obtained by simple washing, thus 
taking advantage of the high specific gravity of gold. 

Streams are carried in aqueducts and thrown in great jets 
against the gravel bluffs to reduce the material to loose 
earth and prepare it for further washing by the same water 
in sluices arranged for the purpose. 

The minerals most common in gold regions are platinum, 
iridosmine, magnetite, pyrite, galenite, ilmenite, chalco- 
pyrite, blende, arsenopyrite, tetradymite, zircon, rutile, 
barite; also in some cases wolfram, scheelite, brookite, mo- 
nazite, and diamond. Platinum and iridosmine accompany 
the gold of the Urals, Brazil, and California; and diamonds 
are found in the gold region of Brazil, and occasionally in 
the Urals, United States, and Australia. Auriferous pyrite 
is worked for its gold in Colorado, and arsenopyrite at 
Deloro in Canada. 

Gold is widely distributed over the globe. In Ammrica, 
it occurs in Brazil (where formerly a greater part of that 
used was obtained) along the chain of mountains which 
runs nearly parallel with the coast, especially near Villa 
Rica, and in the province of Minas Geraes; in New Granada, 
at Antioquia, Choco, and Giron; in Chili; sparingly in Peru 
and Mexico; in Arizona; in the Coast Range, and, much 
more abundantly, in the Sierra Nevada, Cal.; in Oregon, : 
British Columbia, and Alaska; in New Mexico, Colorado, 
and Wyoming, the Black Hills in Dakota, and other parts 
of the Rocky Mountain region; in the Appalachians from 
Virginia to Georgia, a region that formerly produced annu- 
ally nearly a million of dollars; sparingly in Vermont, New 
Hampshire, and other New England States; in Nova Scotia 
along its southern shore, chiefly to the eastward of Halifax; 


GOLD. 125 


in Beauce County, Canada; also, north of Lake Superior; 
and in the gravel of Illinois and Indiana. 

In Europe, it occurs sparingly in Cornwall and Devon, 
England; North Wales, Scotland, and Ireland, formerly in 
the County of Wicklow, where a nugget of 22 ounces was 
found; and in France, very sparingly in the Department of 
Isére; in the sands of the Rhine, the Reuss, and the Aar; 
in Tyrol and Salzburg; on the southern slope of the Pen- 
nine Alps, from the Simplon and Monte Rosa to the Valley 
of Aosta, Northern Piedmont, where nearly 6000 ounces 
were obtained in 1867; more abundantly in Hungary, at 
Kénigsberg, Schemnitz, and Felsobanya, and in T'ransyl- 
vania, at Kapnik, Voréspatak, and Offenbanya; in Spain, 
formerly worked in Asturias; in Sweden, at Edelfors. 

In the Urals are valuable mines at Beresof, and other 
places on the eastern or Asiatic flank of this range, and the 
comparatively level portions of Siberia; also in the Altai 
Mountains. Also in the Cailas Mountains in Little Thibet; 
sparingly in the rivers of Syria and other parts of Asia 
Minor; in Ceylon, China, Japan, Formosa, Java, Sumatra, 
Western Borneo, the Philippines, and New Guinea. 

In Arrica, at Kordofan, between Darfour and Abyssinia; 
also south of Sahara, in the western part of Africa, from 
the Senegal to Cape Palmas; also along the coast opposite 
Madagascar, between the 22d and 35th degrees south lati- 
tude, in the Transvaal Republic. Other regions are Tas- 
mania, New Zealand, and New Caledonia. 


General Remarks.—The most productive gold regions at the present 
time are those of Australia and California. 

In Australia the richest mines are those of Victoria and New South 
Wales. Victoria yielded, in 1856, 3,000,000 ounces, and in 1875, 
1,195,250; New South Wales, in 1875, 227,000 ounces; and all Aus- 
tralia in 1884, $29,000,000. The Australian gold was first made 
known to the world in 1851. The localities discovered were on 
Summer Hill Creek and the Lewis Pend River (near lat. 33° N., 
long. 149°-150° E.), streams which run from the northern flank of 
the Coriobolas down to the river Macquarie, a river flowing westward 
and northward; it was soon afterward found on the Turon River, 
which rises in the Blue Mountains; and finally a region of country 
1000 miles in length, north and south, was proved to be auriferous; 
the country is a region of metamorphic rocks, granite and slates, and 
in many parts abounds in quartz veins. Queensland and South 
Australia, and also Tasmania and New Zealand, afford gold. 

Gold was first discovered in California in the spring of 1848, in 
placer deposits on the American Fork, a tributary to the Sacramento, 


126 DESCRIPTIONS OF MINERALS. 


near the mouth of which Sutter’s establishment was situated. Soon 
the gravels along Feather River, another affluent, 18 or 20 miles 
north, were proved to abound in gold about its upper portions; and it 
was not long after before each stream in succession, north and south, 
along the western slope of the Sierra Nevada was found to flow over 
auriferous sands. The gold region as now developed extends along 
that chain, through the whole length of the great north and south 
valley which hoids the rivers and plains of the Sacramento and San 
Joaquin. It continues south nearly to the Tejon pass, in latitude 
35°, and north beyond the Shasta Mountains to the Umpqua, and 
less productively into Oregon and Washington, and in British Co- 
lumbiaand Alaska. Gold also occurs in some places in the Coast range 
of mountains. Even the site of San Francisco has been found to 
contain traces. North of Shasta Mountain there are mines on the 
Klamath and the Umpqua; and on the sea-shore between Gold Bluff, 
in 41° 30’ south of the Klamath (80 miles south of Crescent City) to 
the Umpqua. 

The yield of gold in the United States up to 1848, before the open- 
ing of the California mines, was $13,250,000; during the year 1848 to 

1879 inclusive, $1,484,000,000; years 1880 to 1884 inclusive $1638,000,- . 
000; making a total of $1,647,013,250. , 

In California, the yield of gold for 1848 was about $45,000 ; for 
1849, over 6,000,000; for 1850, over 36,000,000; and for 1851 to 1857 
inclusive, an average of $55,000,000; after which there was a gradual 
decline from the exhausting of the placer deposits ; in 1868, it was 
$30,000,000; in 1870, $28,500,000; in 1872, $20,000,000; in 1884, 
$13,600,000. 

In Colorado, gold mines occur in Gilpin County, among Archean 
rocks, and much less productively in Clear Creek, Park, Boulder, 
Lake, Summit, Rio Grande, San Miguel, and La Plata counties. 
The yield in 1874 amounted to $2,102,487, of which $1,525,447 were 
from Gilpin County; in 1884, $4,250,000. 

Nevada, where gold was first discovered in 1850, produced from 
the Comstock lode (see p. 128), in 1858, 1859, its first years, $257,000; 
in 1875, about $11,740,000, and the rest of Nevada, $2,256,000, mak- 
ing in all nearly $14,000,000; and in 1876, the Comstock lode yielded 
$18,000,000, and the rest of Nevada about $1,338,000; but all Nevada, 
in 1884, only $3,500,000. 

For the several States and Territorics in 1884, the yield of gold was 
as follows: 


Californidic.t «sess $13,600,000 -| Alaska... ....:c..25s eee $200,000 
COLOV AGO <a es cies eo 4,250,000 | North Carolina........ 157,000 
Nevada....... 3,500,000.) Georgia,. .... -.aeeeee 137,000 
DIREORA 6 ahs wick oe 8,800,000.) Utah coast 0. Go eee 120,000 
LATTA oes “os cub aves cle 2,170,000 | Washington.......... 85,000 
1 5 a >.  1,250.000 | South Carolina........ 57,000 
VS oy it he Rey re 950,000.) WYOmIng. ».c>a0s 5 nee 6,000 


OTEGEN Fon» dian Saks 660,000 | .Virginia,.....55 cba 2,000 
New Mexico....... 300,000 | Alabama, Tenn., etc.. 76,000 


GOLD. 


127 


The yieid of the United States in gold and silver from 1870 to 1884 


was as follows: 








Gold. 
TeeOeriaie cess $33,750,000 
ntl edt e <a aes 34,398,000 
tabard oh aid fe 88,177,395 
Dero eume. wel 89,206,558 
ihe oe Caen ae 88,466,488 
iP a 89,968,194 
Dee GAR cis. bias 42,886,935 
Ui oe eee 44,880,223 
fi. FS a 37,576,030 
Rapitiets Get aes 31,420,262 
VOI vie ven 82,559,067 
De oh ch ges 30,653,959 
Pee ac. os 29,011,318 
Tenet ccs << « 30,000,000 
Pes oe see 30,800,000 


—————E 


Silver. 


$17,320,000 


19,286,000 
19,924,429 
27,483,302 
29 699,122 
81,685,239 
39,292, 924 
45,846,109 
37,248,137 
\87, 082,857 
38,038,055 
42°987,613 
48,133,039 
46,200,000 
48,800,000 


Total. 


$51,070,000 
58,684,000 
58,101,824 
66,689,860 
68,165,610 
71,608,433 
82,179, 859 
90,726,332 
74,824,167 
68,453, 119 
70,592, 122 
78,641,572 
77,144, 357 
76,200,000 
79,600, 000 


The yield of Nova Scotia in 1884 was 16,079 ounces, and in 1885 


22,203 ounces. 


The Central and South American States yielded of 


gold in 1882, Mexico, 986,228; Venezuela, 2,595,077; Colombia, 
8,856,000; Brazil, 741,694; Peru, 119,250; Chili, 163,000; Argentine 
Republic, 78,546; Bolivia, 72,375; making a total of a little more than 


8,560,000 dollars. 


the year 1800, was about $1,872,800,000. 

From 1800 to 1847 inclusive, 48 years, the yield from America, 
Europe, and Africa is stated at $429,200,000; and from 1848 to 1876 
inclusive, 29 years, $3,381,500,000. The largest annual amount was 
produced in the year 1856, in which the yield was $147,600,000; and 
next to this, in 1859, with $144,900,000; as shown in the annexed 
table, giving the amounts in millions of dollars: 


BO ae'cie ba 6 67°5 
TA aivoid > sie <s 87°0 
TBOU main sere’ « « 93°2 
te ea 120°0 
Rito a'es <0 «0% 193°7 
tics os oe o's « 155°0 
yy Se a 127°0 
SOE ace nro 1385°0 


19687 Js ab yar 109 
BOD Sn. s toc .106 
Lee ares 106 
1Gibeacueuces 107 
LB pia asipe se 89 
LSID caascetaen 97 
ERS YE Barge eer bs" 90 
Osh eee es wie 97 
ASST D cette site 90 
DSediss seia-kis:ars 41 


The yield of gold from all America from 1492 to 


2 


WOADWADS 


128 DESCRIPTIONS OF MINERALS. 


The following table gives totals for the years stated : 



































; 5 Mexico 
= United : Other 
Russia. < and South} Australia. a Total. 
States. Arrierices Countries. 

1850. ...| $16,950,000 | $27,500,000 | .......... | .......220. wooed cate) Ole 
1855....| 14,200,000 | 73,700,000 | $5,000,000 | $60,325,000 | $2,500,000 | $155.725,000 
1860....} 15,265,000 | 46,000,000 | 4,500,000 | 53,500,000 | 2,500,000 120,765,000 
1865....} 16,135,000 | 53,225,000} 4,000,000 | 44,100,000} 2,500,000 119,960,000 
1870....} 22,070,000 | 83,750,000 | 2,500,000 | 29,150,000 | 2,500,000 89,970,000 
1875....| 20,000,000 | 40,000,000 3,750,000 28,750,000 2,500,000 95,000,000 
1884....| 22,000,000 | 80,800,000 | 9,400,000 | 28,500,000 | 4,300,000 95,000,000 


Masses of gold of considerable size have been found in North Caro- 
lina. The largest was discovered in Cabarrus County; it weighed 28 
pounds avoirdupois (‘‘ steel-yard weight,” equals 37 pounds troy), and 
was 8 or 9 inches long, by 4 or 5 broad, and about an inch thick. In 
Paraguay pieces from 1 to 50 pounds weight were taken from a mass 
of rock which fell from one of the highest mountains. 

The largest masses of gold yet discovered have been found in aurifer- 
ous gravel. The ‘‘ Blanch Barkley Nugget,” found in South Austra- 
lia, weighed 146 pounds, and only six ounces of it were gangue ; and 
one still larger, the ‘‘ Welcome Nugget,” from Victoria, weighed 
2195 ounces, or nearly 183 pounds, and yielded £8876 10s. 6d. sterling 
of gold. Two others from Victoria weighed 1621 and 1105 ounces. 
In Russia, a mass was found in 1842, near Miask, weighing 96 pounds 
troy ; another of 27 pounds and several of 16 pounds have been found 
in the Urals. The largest mass reported from California weighed 160 
pounds. A remarkably beautiful mass, consisting of a congeries of 
crystals, weighing 201 ounces (value $4000), was found in 1865, seven 
miles from Georgetown, in El Dorado County. 

The origin of gold veins, or rather of the gold in the veins, is little 
understood. ‘The rocks, as has been stated, are metamorphic slates 
that have been crystallized by heat; and they are the hydromica, chlo- 
ritic, and argillaceous, that have been but imperfectly crystallized, 
rather than the mica schist and gneiss, which are well crystallized ; and 
the veins of quartz which contain the gold occupy fissures through 
the slates and openings among the layers, which must have been made 
when the metamorphic changes or crystallization took place. It was 
a period, for each gold region, of long-continued heat (occupying, 
probably, a prolonged age), and also of vast upliftings and disturbances 
of the beds ; for the beds are tilted at various angles, and the veins 
show where were the fractures of the layers, or the separations and 
gapings of the tortured strata. The heat appears not to have been of 
the intensity required for the better crystallization of the more per- 
fectly crystalline schists. The quartz veins could not have been filled 
from below, by injection ; they must have been filled either laterally, 
or from above. In all such conditions of upturning and metamorph- 
ism, the moisture present would have become intensely heated, and 
hence have had great dissolving and decomposing power ; it would 
have taken up silica with alkalies from the rocks (as happens in all 
Geyser regions), along with whatever other mineral substances were 
capable of solution or removal ; and the vapor, thus laden, would have 


SILVER. 129 


filled all open spaces, there to make depositions of the silica and other 
ingredients it contained. These mineral ingredients would have been 
derived either from the rock adjoining the veins or opened spaces, or 
from depths below through ascending vapors. By one or both of 
these means the quartz must have received its gold, pyrite, and ores 
of lead, copper, and other materials—all having been carried into 
the open cavities at the same time with the silica or quartz. The 
pyrite of the vein, by being auriferous, shows that it was crystallized 
under the same circumstances that attended the depositing of the 
gold in strings, crystals, and grains ; and the same is often true of the 
alena. 

z Gold coin of the United States contains 90 parts of gold to 10 of an 
alloy of copper and silver, and an eagle weighs 258 grains. An ounce 
of pure gold is worth about $20.67. 


Calaverite. A bronze-yellow gold telluride ; G. = 9°048 ; Au Te. = 
Tellurium 55°5, gold 44°5 = 100, with a little silver. Occurs mas- 
sive at the Stanislaus Mine, California, and the Red Cloud Mine, 
Colorado, and also the Keystone and Mountain Lion mines, in the 
Magnolia District. 

Itrennerite. Another gold telluride, silver-white to brass-yellow, 
from Nagyag in Transylvania. 

Sylwanite, called also Graphic tellurium (see p. 132). 

Nagyagite. Telluride of lead containing gold (see p. 149). 

Petzite. Telluride of silver and gold, allied to Hessite (p. 182). 


II. SILVER. 


Silver occurs native, and alloyed with gold; also com- 
bined with sulphur, selenium, tellurium, arsenic, antimony, 
bismuth, chlorine, bromine, or iodine; but never as an ox- 
ide, carbonate, sulphate, or phosphate. 


Native Silver. 


Isometric. In octahedrons and other forms. No cleavage 
apparent. Often in filiform and arborescent shapes, the 
threads haying a crystalline character ; also in lamina, and 
massive. 

Color and streak silver-white and shining. Often black 
externally from tarnish. Sectile. Malleable. H. = 2°5-3.. 
G. = 10°1-11°1 (for pure silver, 10°92). 

Composition. Usually an alloy of silver and copper, the 
latter. often amounting to 10 per cent. Also alloyed with 
gold, as mentioned under that metal. <A bismuth silver 
from Copiapo, 8. A., contained 16 per cent. of bismuth. 

B.B. fuses easily to a silver-white globule. Dissolves in 
nitric acid, from which it is precipitated as white chloride 

9 


130 DESCRIPTIONS OF MINERALS. 


on adding hydrochloric acid. A clean plate of copper im- 
mersed in the nitric solution becomes coated with silver. 
Sulphur gases blacken or tarnish silver, producing a sul- 
hide. 
Diff. Distinguished by being malleable ; from bismuth 
and other white native metals by affording no fumes before 
the blowpipe ; by affording a precipitate with hydrochloric 
acid (the chloride of silver, which becomes black on ex- 
posure. 

Obs. Occurs in masses and string-like arborescences, 
penetrating the gangue, or its minerals, in various silver 
mines. It is also found mixed with native copper. Sea- 
water contains 1 part in 100 million; and it has been cal- 
culated that the whole amount in the ocean is not less than 
2,000,000 tons. 

The mines of Norway, at Kongsberg, formerly afforded 
magnificent specimens of native silver, but they are now 
mostly under water. One mass from this locality, at Co- 
penhagen, weighs 500 pounds ; and two other masses have 
been found of 238 and 436 pounds. Other European locali- 
ties are in Saxony, Bohemia, the Hartz, Hungary, Dauph- 
iny. Peru and Mexico also afford native silver. A Mexican 
specimen from Batopilas, weighed when obtained 400 pounds; 
and one from Southern Peru (mines of Huantajaya) weighed 
over 8cwt. Arizona is reported to have produced one mass 
weighing 2700 pounds. In the United States, in the Lake 
Superior region, the silver generally penetrates the copper 
in masses and strings, and is very nearly pure, notwith- 
standing the copper about it. Large masses occur at the 
Idaho Silver Mine, called the Poor Man’s Lode; and in 
strings it is occasionally found in the mines of Nevada, 
California, and Colorado. Native silver has also been ob- 
served at the Bridgewater copper mines, N. J.; and in 
handsome specimens at King’s Mine, Davidson Oo., N. C.; 
Newburyport, Mass. 


Native Amaigam. Silver-white ; consists of silver and mercury ; the 
compounds Ag Hg = Silver 35:1, mercury 64°9, and Ag.Hg, = Silver 
26°5, mercury 73°5, are included. 

Arquerite. A kind from Chili; contains 86°6 per cent. of silver 
(Agi.Hg); from Arqueros ; Vitalle Creek, British Columbia. Another, 
AgisHg, is Kongsbergite, from Kongsberg, Sweden ; Arqueros, Chili. 
Another has been called Bordosite. 


SILVER. 131 


SULPHIDES, SELENIDES, TELLURIDES, ANTIMONIDES. 
Argentite.—Silver Glance. Sulphuret of Silver. 


Isometric. In dodecahedrons more or less modified. 
Cleavage sometimes apparent parallel to the faces of the 
dodecahedron. Also reticulated and massive. 

Lustre metallic. Color and streak blackish lead-gray ; 
streak shining. Verysectile. H. = 2-2°5. G.= 7:19-7°4. 

Composition. When pure, Ag,S= Sulphur 12°9, silver 
87°1. B.B. on charcoal in O.F. intumesces, gives off the 
odor of sulphur, and finally affords a globule of silver. 

Diff. Resembles some ores of copper and lead, and other 
ores of silver, but is distinguished by being easily cut, like 
lead, with a knife ; and also by affording a globule of silver 
on charcoal by heat alone. Its specific gravity is much 
higher than that of any copper ores. 

Ods. This important ore of silver occurs in Europe prin- 
cipally at Annaberg, Joachimsihal, and other mines of the 
Erzgebirge; at Schemnitz and Kremnitz, in Hungary, and 
at Freiberg in Saxony. It is acommon ore at the Mexican 
silver mines, and also in the mines in South America. It 
occurs in Arizona, with chalcocite, at the Heintzelman 
Mine; in Nevada; in Colorado, Clear Creek Co., near 
Georgetown. A mass of “‘sulphuret of silver” is stated 
by Troost to have been found in Sparta, Tennessee. 

Acanthite. An orthorhombic silver sulphide, Ag.S, from Joachim- 
stahl. Daleminzite. Another, from near Freiberg. 

Stromeyerite. Steel-gray silver-copper sulphide, Ag.S-+Cu.S = 
Sulphur 15-7, silver 53:1, copper 31°2 = 100; H = 2°5-8; G@. = 6°26; 
B.B. fuses and gives in the open tube an odor of sulphur, but yields 
a silver globule only by cupellation with lead. Peru, Silesia, Chili, 
Siberia, and Arizona. 

Sternbergite. Silver-iron sulphide, containing 30 to 385 per cent. 
of silver; highly foliated, resembling graphite, and like it leaving a 
tracing on paper ; the thin Jamine flexible ; color pinchbeck brown ; 
streak black; G. = 4°215. Joachimsthal and Johanngcorgenstadt ; 
Arizona. Argyropyrite (G. = 4:206) from Freiberg, and Friesette 
from Joachimsthal, are varieties of sternbergite. Argentopyrite con- 
tains 26°5 of silver. and is a related species, from Andreasberg. 

Naumannite. Silver-lead selenide, in iron-black cubes and mas- 
sive ; G. = 8; contains 11-16 per cent. of silver. The Hartz. 

Hessite. Silver telluride, Ag.Te = Tellurium 37:2, silver 62°8 = 
100. Color between lead-gray and steel-gray; sectile; G. = 8°3—8°6; 
B.B. in the open tube, faint sublimate of tellurous acid ; on charcoal 
with soda a silver globule. The Altai; at Nagyag and Retzbanya ; 


132 DESCRIPTIONS OF MINERALS. 


Coquimbo, Chili; Calaveras Co., Cal.; Red Cloud Mine, Col.; 
Kearsarge Mine, Dry Cafion, Utah. 

Petzite, A hessite with the silver replaced in part by gold. G. = 
8°7-9°4. Between steel-gray and iron-black. Variety from Golden 
Rule Mine afforded Genth Tellurium 32°68, silver 41°86, gold 25°60 = 
100°14. Occurs at the same localities with hessite. 

Tapalpite. Telluride of bismuth and silver from Mexico. 

Sylvanite or Graphic Tellurium. Gold-silver telluride (Ag, Au) 
Te; = (if Ag : Au = 1:1) Tellurium 55'8, gold 28°5, silver 15°7 = 100. 
Color and streak steel-gray to silver-white, and sometimes nearly 
brass-yellow; H. =1°5-2; G. = '7:9-8°38 ; called graphic because of 
a resemblance in the arrangement of the crystals to writing characters. 
Transylvania ; Calaveras Co., Cal.; Red Cloud, Grand View, and 
Smuggler Mines, Col. 

Stitete. Crystals hexagonal; silver telluride; Ag:.Te? Transyl- 
vania, 

Hucairite. Silver-copper selenide, containing 42-45 per cent. of 
sitver ; color between silver-white and lead-gray ; easily cut by the 
knife. From Sweden and Chili. 

Dyscrasite, or Antimonial Silver. Silver antimonide ; contains 78. 
to 85 parts of silver, and has nearly a tin-white color; G. = 9°4-9°8; 
B.B. fumes of antimony pass off, leaving finally a globule of silver. 
Wolfach, Wittichen ; Andreasberg ; Allemont in Dauphiny ; Bolivia, 
S.A 


 Huntilite. A silver arsenide; dark gray to black, amorphous; 
G. = 7°47. Silver Islet, L. Superior. Mcfarlanite is impure huntilite. 
Animikite. A silver antimonide, Silver Islet, L. Superior. 


SULPHARSENATES. SULPHANTIMONATES. 
Pyrargyrite.—Ruby Silver. Dark Red Silver Ore. 


Rhombohedral. RA R = 108° 42’; RAi-2 = 129° 39’, 
Cleavage parallel to Rk imperfect. Also massive. Black to 
dark cochineal-red, with the streak cochi- 
sa neal-red and lustre splendent metallic-ada- 
3 mantine. H. = 2-2°5. G.=5:7-5°9. 

Composition. Ag,S,Sb (= 3Ag,S + 
| $b,S,)= Sulphur 17:7, antimony 22:5; 

a2) 42 | silver 59-8 = 100. 

B.B. fuses very easily ; on charcoal a 
white deposit of antimony oxide, and with soda a globule of 
silver. In an open tube, sulphurous fumes that redden lit- 
mus paper. 

Diff. Its red streak, and its reactions for antimony and 
silver, are distinctive. 

Obs. Occurs at Andreasberg ; also in Saxony; Hungary; 
Cornwall ; Mexico; Chili; Nevada at Washoe; abundant 


SILVER. 133 


about Austin, Reese River; at Poor Man’s Lode, and else- 
where, in Idaho; Arizona. 

Proustite, or Light Red Silver Ore, is a related ore con- 
taining arsenic in place of much or all of the antimony, 
and having a light-red color, splendent lustre ; G. = 5°4-5°6. 
Composition, Ag,S,As = Sulphur 19:4, arsenic 15:1, silver 
65°5 = 100. B.B. gives a garlic odor. Occurs with 
pyrargyrite at the above-mentioned localities, and in micro- 
scopic crystals in Cabarrus Co., N. C. 


Stephanite.—Brittle Silver Ore. Black Silver. 


Orthorhombic. JA J=115° 39’. No perfect cleavage. 
Often in compound crystals. Also massive. Streak and 
color iron-black, H. = 2-2°5. G. = 6°27. . 

Composition. Ag.S,Sb (= 5Ag,8 + Sb,S,) = Sulphur 
16:2, antimony 15°3, silver 68°5. B.B. an odor of sulphur 
and also fumes of antimony, yielding a dark metallic glob- 
ule from which silver may be obtained by the addition of 
soda. Soluble in dilute nitric acid; the solution indicates 
the presence of silver by silvering a plate of copper. 

Obs. Occurs with other silver ores at Freiberg, Schnee- 
berg, and Johanngeorgenstadt, in Saxony; also in Bohe- 
mia, and Hungary. An abundant ore in Chili, Peru, 
and Mexico; also in Nevada, at the Comstock Lode, 
and at Ophir, and Mexican mines, in the Reese River and 
Humboldt, and other regions; in Colorado, in Clear Creek 
Co. and elsewhere ; in Idaho; Arizona. Sometimes called 
black silver. 

Polybasite. Near stephanite in color, specific gravity, and composi- 
tion, but contains some arsenic and copper, with 64 to 72°2 per cent. 
of silver; orthorhombic, and usually in tabular hexagonal prisms, 
without distinct cleavage; G. = 6°214. Freiberg; Przibram ; Mexico; 
Chili; the Reese mines in Nevada; Idaho; Arizona. 

Miargyrite. Antimonial silver sulphide, containing but 36°5 per 
cent. of silver, and having a dark cherry-red streak, though iron-black 
in color. H. = 2-2°5; G. = 5°2-5°4 ; B.B. on charcoal gives off fumes 
of antimony and an odor of sulphur; and in the oxidating flame, a 
globule is left which finally yields a button of pure silver. Saxony ; 
Bohemia ; Spain; Mexico ; Arizona. 

Brongniardite. In regular octahedrons and massive ; color grayish- 
black; G@. = 5°95; contains about 25 per cent. of silver, with lead, 
antimony, and sulphur. From Mexico. 

Polyargyrite. Isometric, having cubic cleavage ; near polybasite in 
composition = 12A¢.$8-+8b.8;. Wolfach in Baden. 

Fretestebenite. A monoclinic antimonial silver-lead sulphide; color 
light steel-gray ; G. = 6-6.4; H. = 2-2°5; contains 22 to 24 per cent. 


134 DESCRIPTIONS OF MINERALS. 


of silver. Saxony; Transylvania; Spain; Arizona. Déiaphorite is 
the same in composition, but is orthorhombic. 

Pyrostilpnite. Another monoclinic silver ore; in delicate crystals 
grouped like stilbite ; color fire-rred. Contains 62°3 per cent. of silver. 
Freiberg ; Andreasberg; Przibram. 

Schirmerite. Lead-gray to iron black ; contains silver, lead, with 
much bismuth and sulphur. Red Cloud Mine, Col., and elsewhere. 


CHLORIDES, BROMIDES, IODIDEs. 
Cerargyrite.—Horn Silver. Silver Chloride. 


Isometric. In cubes, with no distinct cleavage. Also 
massive, and rarely columnar ; often incrusting. H. = 2- 
15; G.=5:'3-5°5. Color gray, passing into green and 
blue; looking somewhat like horn or wax, and cutting 
like it. Lustre resinous, passing into adamantine. Streak 
shining. ‘Translucent to nearly opaque. 

Composition. Ag Cl= Chlorine 24°7, silver 75°3. Fuses in 
the flame of a candle, and emits acrid fumes. B.B. affords 
silver easily on charcoal. A plate of iron rubbed with it is 
silvered. 

Obs. A very common ore and extensively worked in the 
mines of South America and Mexico; also abundant in 
Nevada; in Idaho at Poor Man’s Lode; in Arizona; Utah; 
Colorado; in Saxony, Siberia, Norway, the Hartz, and Corn- 
wall. A variety containing mercury occurs at the mine 
La Julia, Northern Chili. 


Bromyrite or Bromic Silver. Silver bromide, Ag Br = Bromine 
42°6, silver 57°4= 100; H. = 2-8; G. = 58-6. With the preceding, 
in Mexico and Chili. 

Hmbolite. Silver chlorobromide, resembling cerargyrite; H. = 1- 
1°5; G. = 5°3-5°8; color asparagus to olive green; contains 51 p. c. of 
silver chloride to 49 of bromide. Common in Chili; also found in 
Chihuahua, Mexico. 

lodyrite. Silver iodide, Ag I = Iodine 54:0, silver 460 = 100; 
bright yellow; lustre not metallic, like the preceding; G. = 5°5-5°7. 
Spain; Chili; Mexico; the Cerro Colorado Mine, Arizona. Jodobrom- 
a is a yellow brom-iodo-chloride of silver, in octahedrons; from near 

assau. 

Tocornalite. A silver-mercury iodide. Chili. ° 


General Remarks.—The chief sources of the silver of commerce are 
(1) Native silver; (2) the sulphide, Argentite (or vitreous silver); four 
species among the sulpharsenites and sulphantimonites, viz., (8) 
Prousttte, or the light-red or ruby-silver ore, and (4) Pyrargyrite, or 
dark-red silver ore; (5) Kreteslebenite; (6) Argentiferous tetrahedrite, 
which contains sometimes 10 to 30 per cent. of silver; (7) Stephanite or 


SILVER. 135 


brittle silver ore; (8) the chloride, called horn-silver or Cerargyrite,; 
(9) the bromide and chlorobromide, Bromyrite and Hmbolite, common 
in Chili and Mexico, especially the latter, along with the rarer iodide; 
(10) Argentiferous Galenite, often called silver-lead ore. Of the other 
ores of silver mentioned beyond, the most important are Arquerite, 
common especially in Chili, and Polybasite. 

Silver ores occur in rocks of all ages and kinds, from gneiss, 
granite, and mica schist, to sandstones, shales, and limestones, and 
from Archean to Tertiary. Among the above-mentioned ores, 
argentiferous galenite, or silver-lead ore, is of very prominent import- 
ance, and as both of its metals, the lead and silver, are valuable and 
the reduction easy, it is worked when ccntaining but five ounces of 
silver to the ton. 

The veins of silver ores in gneiss and metamorphic rocks, away 
from eruptive kinds, usually have galenite as the chief ore, with 
sulphides of iron,-zinc, and copper as associates, and quartz, and 
often more or less fluorite or barite, as the gangue. Other silver 
ores, the sulphides, arsenical and antimonial, may also be present 
and abundant; yet when so, they are mostly if not wholly second- 
ary products, and are accompanied generally by lead carbonate and 
sulphate. But in most rich silver regions the veins, whether inter- 
secting metamorphic, fragmental or calcareous formations, are con- 
nected with eruptive rocks. Yet even in such cases galenite is 
usually an abundant vein-material, and may have been a source of 
much of the silver. Sulphur, arsenic, and antimony have been 
among the materials introduced, and these agents, together with car- 
bonic acid, phosphoric acid, oxygen and chlorine, derived from below 
or above, have carried on the changes. 

The silver-producing veins of the eastern border of North America 
are mostly veins in metamorphic rocks having no connection with 
eruptive rocks, and they have yielded little silver. The Michigan 
region and those of productive mines in western America over the sum- 
mit and western slope of the great mountain range from Patagonia 
to British America are for the most part in regions intersected by 
eruptive rocks, and to this fact owe their existence. Moreover, ex- 
cluding the Michigan region, they are much alike, through the five 
thousand miles, in their characters, their ores, and the associated 
eruptive rocks. ‘The eruptives are chiefly andesyte, rhyolyte, dacyte, 
and doleryte, or basalt. Silver chloride is usually a common ore, 
especially in the upper part of the veins or deposits; and a mixture of 
it with more or less of lead carbonate, often with iron oxide (from the 
decomposition of iron or copper sulphides) and with limestone and 
other material (from the decomposed rocks), makes the ore called car- 
bonate. Other lead ores, the ruby-silver ores, argentite, stephanite, 
tetrahedrite, and the rest of those above enumerated, are common in 
the veins. Gold is often present, also copper and zinc ores. Lime- 
stone strata are common repositories of the ores; and this is attributed 
to the fact that limestone is easily eroded by acid solutions and 
vapors; so that, if intersected by a fissure up which such vapors or 
solutions are ascending, cavities or chambers will be made in it, and 
passageways along the joints and seams for the reception of the ore 
deposits. In the Washoe region, Nevada, and many others, there is 


136 DESCRIPTIONS OF MINERALS. 


no limestone. The chlorine of the silver chloride is supposed to have 
come from superficial saline waters, like those of the Great Salt Lake, 
salt being a sodium chloride; carbonic acid for the lead carbonate, 
from the limestone; the sulphur, from the decomposition of sulphides, 
as galenite, pyrite, etc.; the arsenic, antimony, with part of the sul- 
phur, from the ascending vapors; the silver, from ores in the rock 
making the walls of the fissures somewhere below at large or shallow 
depths (and argentiferous galenite may have been the most prominent 
source). Secondary products are still in progress in the surface por- 
tion of most veins; and in the deeper, if there is some little heat to 
favor change. 

The richest mines of Chili are not far distant from Copiapo, in the 
mountains north of the valley of Huasco, The mines of Mt. Chanar- 
cillo, about 16 leagues south of Copiapo, abound in horn silver, and 
begin to yield arsenio-sulphides at a depth of about 500 feet. The 
mines of Punta Brava, which are nearer the Cordilleras, afford the 
arsenical and antimonial ores. In Peru, the principal mines are in 
the districts of Pasco, Chota, and Huantaya. ‘Those of Pasco are 
15,700 feet above the sea, while those of Huantaya are in a low desert 
plain, near the port of Yquique, in the southern part of Peru. The 
ores afforded are the same as in Chili. The mines of Huantaya 
are noted for the large masses of native silver they have afforded. 
Silver is obtained in Peru, also, in the districts of Caxamarca, Pataz, 
Huamanchuco, and Hualgayoc. The Potosi mines in Bolivia occur in 
a mountain of argillaceous shale, whose summit is covered by a bed 
of argillaceous porphyry. The ore is the ruby silver, and argentite 
with native silver. ‘The district of Caracoles, between Chili and 
Bolivia, yields much silver. 

In Europe the principal mines are those of Spain, the province 
of Guadalajara, where the ore is chiefly freieslebenite; of Kongs- 
berg in Norway; of Saxony, chiefly at Freiberg, Ehrenfriedens- 
dorf, Jobanngeorgenstadt, Annaberg, and Schneeberg; in the Hartz; 
in Austria, Hungary, Transylvania, and the Banat; and Russia. The 
mines of Kongsberg, in Norway, occur in gneiss and hornblende 
slate, in a gangue of calcite. They were especially rich in native 
silver. 

In the Tyrol, Austria, argentite, argentiferous tetrahedrite, and mis- 
pickel occur in a gangue of quartz, in argillaceous schist. The Hun- 
garian mines, at Schemnitz and Kremnitz, occur in syenyte and horn- 
blende porphyry, in a gangue of quartz, often with calcite or barite 
(heavy spar), and sometimes fluorite. The ores are argentite, tetrahe- 
drite, galenite, blende, pyritous copper and iron; and the galenite and 
copper ores are argentiferous. France produces some silver from ar- 
gentiferous galenite at Huelgoet in Brittany, and the mines of Pontgi- 
baud, Puy-de-Dome. 

The Russian mines are in Kolyvan in the Altai, and Nertschinsk in 
the Daouria Mountains, Siberia (east of Lake Baikal). The Daouria 
mines afford argentiferous galenite which is worked for its silver; 
it occurs in a crystalline limestone. The silver ores of the Altai occur 
in Silurian schists in the vicinity of porphyry, which contain also 
gold, copper, and lead ores. 

The mines of Mexico are most abundant between 18° and 24° north 


SILVER. 137 


latitude, on the back or sides of the Cordilleras, and especially the 
west side; and the principal are those of the districts of Guanaxuato, 
Zacatecas, Fresnillo, Sombrerete, Catorce, Oaxaca, Pachuca, Real del 
Monte, Batopilas, and Tasco: The vein of Guanaxuato, the most 
productive in Mexico, intersects argillaceous and chloritic shale, and 
porphyry; it affords one fourth of all the Mexican silver. The Valen- 
cian mine is the richest in Guanaxuato. The Pachuca, Real del 
Monte, and Moro districts are near one another. 

In the United States the chief silver mines are in Colorado, Nevada, 
Utah, New Mexico; Arizona, Montana, Idaho. For regions, see List 
of Localities, beyond. The copper mines of northern Michigan afford 
much native silver, and also the native gold of the various gold mines 
of the country. 

For the years previous to 1859 the whole yield of. silver from the 
United States mines is estimated at $1,000,000. The following are 
the amounts for the succeeding years to 1870: 


Dea eae Fels Ca... >. BLUUU0U (COU actress eu st $11,250,000 
BOR odes we. so 0 « AU UUs fh LOU. "a ad etein YA cide 10,000,000 
jal NE OP oR LUG OU kOU Ls ans sc eg hs of e tee 13,550,000 
ot ea MMI AN NT a Pe LOUG a a suits once n s.cio:47e 12,000,000 
BOs cabs 5 ois Rakete Wie - REMC LOO es ove artes ce «wn gate 13,000,000 
ood Aaa i oA Ua hdl ay es ait tine eta ogg 17,320,000 


The Comstock lode, in the Washoe region, Nevada, was first opened 
in 1859, and contributed to the silver of the world, in 1860, about 
$1,000,000. -Virginia City grew out of it. In 1861 other mining 
regions were discovered in Humboldt Co., 150 miles north-east of Vir- 
ginia City, and in 1862 the Reese River discoveries (at the present town 
of Austin) were made; others soon followed, among which, those in 
the Eureka district, 60 miles east of Austin, have proved of great 
value. Nevada Territory in 1875 yielded of silver $14,922,350, and 
in 1876, $20,570,078. The amount fell off in 1878, owing to the work- 
ing out of the Comstock lode, and in 1882 it was only $6,750,000. 

For the yield of the United States in silver since 1870, see page 127. 

The yield of the Western States and Territories in 1876 and 1884 
is reported as follows: 


1876. 1884. 
a $500,000 $4,500,000 
MPEERLIF re rcs IS. TERR 1,800,000 3,000,000 
NG es 0 Se mr a 8,000,000 16,000,000 
a ae ek cei et we eects Se Melee 150,000 
si) eS a a 300,000 2,720,000 
MT lahore as a a ucae ee wee se 2 ws etd 800,000 7,000, 000 
SARS SRS 6s sas Seger it ar 20,570,078 5,600,000 
SIEECEIOOS 0 Use ccc oa wk sl deeeewe 400,000 3,000,000 
ye da Ces . oe cele ods bike MiNi es die 20,000 
MURR TPEE UOC cece. UU Cc ees 8,351,520 6,800,000 


PUEDE ES Fl ba ca ce cece ssccoccs sctandteld 1,000 


138 DESCRIPTIONS OF MINERALS. 


In the Report of the U. S. Mint for 1885 the yield of the world 
in 1884 is given approximately, as follows: 


Morway-and Sweden.j.. 5.4% b.. ssenn yea $340, 962 
Austria-Hungary, viienon eve ahem ie tee. 2,054,070 
German yi vi.8 sa) no Sele es Save eeeneee 10,311,659 
PRUSSIA «68 coo 0 acta einitgin gd hin hee el eee 888,000 
MPFADCEs. ss xo's «Wein alec eb tenis cae eh baie 264,275 
MEAT ies’, wioin bl sw tint an tein de Rot eee eee 17,949 
SPAIN Aves ease 4Us os at babe eh eee wee 148,000 
FTKGY oF <i taalk 'sm'ae bs scintrah' swe eine ate ree ie 89,916 
ARAL R LIB cow icles ic ds ate ela bla fo bist s ote 115,960 
EUVATL cok g Rise Bike adeaur a leiy ey ckee aa has on eee 877,772 
FAGT 1s fn SS sawe Ve Meas Ye CE nb oe Pee i 908, 000 
BOUVIa: cist se eee th eae ae Baca kh eee 16, 000, 000 
CHI a es obs oa seb ee cine ee ee ae ee 5,325,000 
Argentine Republic.:ic. vs Ga ee kes eee 420,225 
Colombia) 2s-..25 ss saucsgaeuit «aoe eee ae 760,000 
DI OXICO aia a's oie eh ip.» O) oils gon Sik ee 27,257,885 
United Statesic. ic. dean cat eee tee ee ee 48,800,000 
CJADAGA Se stat Waa oe REE PE Ue cee Dene 68,205 
s Totaly Wis Aaa os aes eee ee $115, 147,878 


The following table gives, in dollars, the estimated value of the 
world’s production of silver in recent years: 








Russia. |United States. habe aetna C Pes Total. 
1855...| 600,000 weeseeee. | 30,000,000 | 10,000,000 40,600,000 
1860...) 650,000 150,000 | 30,000,000 | 10,000,000 40,800,000 
1865...| 700,000 | 11,250,000 | 30,000,000 | 10,000,000 51,950,000 
1870...| 575,000 | 17,820,000 | 25,000,000 | 10,000,000 57,895,000 
1875...| 500,000 | 81,635,000 | 25,000,000 | 10,000,000 67,185,000 
1882...| 324,000 | 46,800,000 | 48,651,000 | 16,000,000 | 111,775,000 
1884...| 888,000 | 48,800,000 | 51,740,000 | 14,222,000 | 115,150,000 


The world’s production of silver from 1800 to 1880 is estimated at 


$799,100,000 (average $26,637,000); from 1830 to 1851, inclusive, at 
$600,400,000 (average $27,300,000); from 1852 to 1877, twenty-six 
years, $1,341,800. 000 (average $51,608,000); from 1882 to 1884, in- 
clusive, $343,893,000 (average $114,631 000). 

The relative value of silver and gold, about 1500, was 1: 11°25; 
1600, 1:12; 1700, 1:15; 1800, 1:15; 1820, 1:15°5; 1840, 1:15°%5; 
1860, °1:15°35; 1875, 1:16; 1878, 1:18; 1879, 1:18°4: 1886 setae 
Herodotus made the ratio 1:18; Plato, 1:12; Menander, 1:10; and 
in Ceesar’s time it was 1: 9. 


PLATINUM. 139 


Native Platinum. 


Isometric: but crystals seldom observed. Usually in 
flattened or angular grains or irregular masses. Cleavage 
none. 

Color and streak pale or dark steel-gray. Lustre metal- 
lic, shining. Ductile and malleable. H.=445. G.= 
16-19; 17°108, small grains; 17°608, a mass. (When pure, 
21°15.) Often slightly magnetic, and some masses will 
take up iron filings. 

Composition. Platinum is usually combined with more or 

less of the rare metals iridium, rhodium, palladium, and 
osmium, besides copper and iron, which give it a darker 
color than belongs to the pure metal and increase its hard- 
ness. A Russian specimen afforded: Platinum 78°9, iri- 
dium 5:0, osmium and iridium 1°9, rhodium 0°9, palladium 
0:3, copper 0°7, iron 11:°0= 98°75. California platinum 
afforded: Platinum 85°50, iridium 1:05, osmiridium 1°10, 
rhodium 1°00, palladium 0°60, copper 1°40, iron 6°75 ; but 
some of California yields only 50 per cent. of platinum. 
- Platinum is soluble in heated aqua regia. It is one of 
the most infusible substances known, being B.B. unaltered. 
Slightly magnetic, and this quality is increased by the iron 
it may contain. ; 

Diff. Platinum is at once distinguished by its malleability, 
specific gravity, and extreme infusibility. 

Obs. Platinum was first detected in 1735 in grains in the 
alluvial deposits of Choco and Barbacgoa in New Granada 
(now U. States of Colombia), within two miles of the north- 
west coast of South America, where it received the name 
platina, derived from the word plata, meaning silver. Al- 
though before known, an account by Ulloa, a Spanish 
traveller in America in 1735, directed attention in Europe, 
in 1748, to the metal. It is now obtained in Novita, and 
at Santa Rita and Santa Lucia, Brazil. It has been af- 
forded most abundantly by the Urals. It occurs also on 
Borneo; in the sands of the Rhine; in Australia; in 
those of the river Jocky, St. Domingo; in traces in the 
U. States, in Rutherford Co., N. Carolina; Virginia; 
Georgia ; at La Francois Beauce, Canada; with gold near 
Point Orford, on the coast of Northern California (probably 
derived, according to W. P. Blake, from serpentine rocks); 
Wood R. Co., Idaho; in British Columbia. A nugget, of 


140 DESCRIPTIONS OF MINERALS. 


104°4 grams, found near Plattsburgh, N. Y., afforded Col- 
lier 46 p. c. of platinum and 54 p. c. of chromite, and had 
G. = 10°446. 

The Ural localities of Nischne Tagilsk and Goroblagodat 
have afforded much the larger part of the platinum of com- 
merce. It occurs, as elsewhere, in alluvial beds; but the 
courses of platiniferous alluvium have been traced toa great 
extent up Mount La Martiane, which consists of crystalline 
rocks, and is the origin of the detritus. One to three pounds 
are procured from 3700 pounds of sand. ‘The production 
of the U. States in 1884 was not over 150 troy ounces. 

Though commonly in small grains, masses of considerable 
size have occasionally been found. A mass weighing 1088 
grains was brought by Humboldt from South America and 
deposited in the Berlin Museum. Its specific gravity was 
18°94. In the year 1822, a mass from Condoto was de- 
posited in the Madrid Museum, measuring 2 inches and’ 4 
lines in diameter, and weighing 11,641 grains, A more 
remarkable specimen was found in the year 1827 in the 
Urals, not far from the Demidoff mines, which weighed 
11:57 pounds troy; and similar masses are now not uncom- 
mon. The largest hitherto discovered weighed 21 pounds 
troy. 

Russia has afforded annually about 35 cwt. of platinum, 
which is about five times the amount from Brazil, Borneo, 
Colombia, and St. Domingo. Borneo affords about 500 
pounds per year. 

The infusibility of platinum and its resistance to the ac- 
tion of the air, and moisture, and most chemical agents, 
renders it of great value for the construction of chemical 
and philosophical apparatus. ‘The large stills employed in 
the concentration of sulphuric acid are now made of plati- 
num; but such stills are gilt within, since platinum when 
unprotected is acted upon by the acid, and soon becomes 
porous. It is also used for crucibles and capsules in chemi- 
cal analysis; for galvanic batteries; as foil, or worked into 
cups or forceps, for supporting objects before the blowpipe. 
It alloys readily when heated with iron, lead, and several of 
the metals, and is also attacked by caustic potash and phos- 
phoric acid, in contact with carbon; and consequently there 
should be caution when heating it not to expose it to these 
agents. 

It is employed for coating copper and brass; also for 


PALLADIUM. 141 


painting porcelain and giving it a steel lustre, formerly 
highly prized. It admits of being drawn into wire of ex- 
treme tenuity. 

Platinum was formerly coined in Russia. The coins had 
the value of 11 and 22 rubles each. 

This metal fuses readily before the ‘‘ compound blow- 
pipe ;” and Dr. Hare succeeded in 1837 in melting twenty- 
eight ounces into one mass. ‘lhe metal was almost as mal- 
leable and as good for working as that obtained by the other 
process ; it had a specific gravity of 19°38. He afterwards 
succeeded in obtaining from the ore masses which were 90 
per cent. platinum, and as malleable as the metal in ordinary 
use, though somewhat more liable to tarnish, owing to some 
of its impurities. Deville and Debray have perfected this 
process, and have melted over 25 pounds of platinum in less 
than three quartersof an hour. In the process the osmium 
present is oxidized and thus removed. 


Platin-iridium. Grains of iridium have been obtained at Nischne 
Tagilsk, consisting of 76°8 iridium and 19°64 platinum, with some 
- palladium and copper. A similar platin-iridium has been obtained at 
Ava, in the East Indies. Another, from Brazil. contained 27°8 iridium, 
55°5 platinum, and 6°9 rhodium. Reported from Mendocino and 
Trinity Cos., Cal. 

Iridosmine. A compound of iridium and osmium from the platinum 
mines of Russia, South America, the East Indies, and California ; in 
pale steel-gray hexagonal prisms, but usually in flat grains ; H. = 6°7; 
G. = 19°5-21°1; malleable with difficulty. One variety, called Nef- 
danskite, contains iridium 46°8, osmium 49°3, rhodium 3:2, iron 0°7, 
Another, Stsserskite, iridium 25°1, osmium 74°9, and iridium 20, os- 
mium 80. But analysis affords also from 0°5 to 12°3 of rhodium, and 
0-2 to 6-4 of the rarer metal ruthenium, with traces usually of plati- 
num, copper, and iron. The grains are distinguished from those of 
platinum by their superior hardness, and also by the peculiar odor of 
osmium when heated with nitre. Iridosmine is common with the gold 
of Northern California, and injures its quality for jewelry. Occurs 
sparingly in the gold washings on the rivers Du Loup and Des 
Plantes, Canada. 

The metal iridium is extremely hard, and is used, as well as rhodium, 
for points to the nibs of gold pens, for the knife-edges of fine balances, 
ete. Thestandard meters of the International Commission on Weights 
and Measures consist of 90 per cent. of platinum and 10 of iridium. 

Laurite. In minute octahedrons. A ruthenium sulphide, with 3 
per cent. of osmium. From platinum sands of Borneo and Oregon. 


Palladium. 


Isometric. In minute octahedrons. Occurs mostly in 
grains, sometimes composed of divergent fibres. Color 


142 DESCRIPTIONS OF MINERALS. 


steel-gray, inclining to silver-white. Ductile and malle- 
able. H.=4°5-5. G. = 11°3-12°2 (the latter after ham- 
mering). 

Consists of palladium, with some platinum and iridium. 
Fuses with sulphur, but not alone. 

Obs. Occurs in Brazil with gold, and is distinguished 
from platinum, with which it is associated, by the divergent 
structure of its grains. It was discovered by Wollaston, in 
1803. Selenpalladite, or Allopalladium, is from Tilkerode 
in the Hartz; reported also from St. Domingo and the Urals. 
Porpezite is palladium gold, or gold containing 7 to 11 per 
cent. of palladium. 

This metal is malleable, and when polished has a whitish 
steel-like lustre which does not tarnish. A cup weighing 

+ pounds was made by M. Bréant in the mint at Paris, and 
is now in the garde-meudle of the French crown. In hard- 
ness it is equal to fine steel. 1 part fused with 6 of gold 
forms a white alloy ; and this compound was employed, at 
the suggestion of Dr. Wollaston, for the graduated part of 
the mural circle constructed by Troughton. for the Royal 
Observatory at Greenwich. Palladium has been employed 
also for certain surgical instruments. 


MERCURY. 


Mercury occurs native; alloyed with silver forming na- 
tive amalgam; in combination with sulphur, selenium, 
chlorine, or iodine; and with sulphur and antimony in some 
tetrahedrite. Its ores are completely volatile, excepting 
when silver or copper is present. 


Native Mercury, or Quicksilver. 


Isometric. In fluid globules scattered through the 
gangue. Color tin-white. G. when pure = 13°58. Be- 
comes solid and crystallizes at a temperature of — 39° F., 
and then G. = 14-4-14°5. 

Mercury, or quicksilver, as it is often called (a transla- 
tion of the old name ‘‘argentum vivum”), is entirely 
volatile B.B., and dissolves readily in nitric acid. 

Obs. Occurs at the different mines of this metal, at 
Almaden in Spain, Idria in Carniola (Austria), in Hungary, 
Peru, California, and Colorado. Usually in disseminated 


MERCURY. 143 


globules, but sometimes accumulated in cavities so as to be 
dipped up in pails. . 

Used for the extraction of gold and silver ores. Also 
employed for silvering mirrors, for thermometers and 
barometers, and for various purposes connected with medi- 
cine and the arts. 


Native Amalgam. Sec page 130. 


Cinnabar.—Mercury Sulphide. 


Rhombohedral ; R A & = 72° 36’. Cleavage lateral, high- 
ly perfect. Crystals often tabular, or six-sided prisms. 
Also massive; sometimes in earthy coatings. 

Lustre unmetallic, of crystals adamantine ; often dull. 
Color bright red to brownish red, and brownish black. 
Streak scarlet-red. Subtransparent to nearly opaque. 
H. = 2-2°5. G.=9; impure, 8°5 and less. Sectile. 

Composition. HgS,=Sulphur 13°8, mercury 86°2. 
Often impure. The liver ore, or hepatic cinnabar, contains 
some carbon and clay, and has a brownish streak and color. 
B.B. volatilizes entirely when pure. 

Diff. Distinguished from red oxide of iron and chromate 
of lead by vaporizing B.B.; from realgar by alliaceous fumes 
on charcoal. 

Obs. The ore from which the principal part of the mer- 
cury of commerce is obtained. When pure identical with 
the pigment vermilion. Occurs mostly in connection with 
siliceous, hydromica, and argillaceous slates, or other stra- 
tified deposits, both the most ancient and those of more 
recent date. Too volatile to be expected in any abundance 
in proper igneous or highly crystalline rocks, yet has been 
found sparingly in granite. 

The localities are mentioned beyond. 


Metacinnabarite. The same compound as cinnabar, but different 
in crystallization. Redington Mine, Lake Co., Cal. Guadalcazarite, 
from Mexico, is a variety. 

Tiemannite. Dark steel-gray mercury selenide. The Hartz; 
vicinity of Clear Lake, Cal., and Utah. 

Onofrite. Massive, blackish-gray, metaliic; G. = 7°62; mercury 
sulpho-selenide. San Onofre, Mexico; Marysvale, Utah. 

Coloradoite. Grayish-black mercury telluride; G. = 8°627. Key- 
stone and Mountain Lion and Smuggler Mines, Col. 

Calomel or Horn Quicksilver. Mercury chloride; tough, sectile ; 
light yellowish or grayish ; lustre adamantine; translucent or sub- 


144 DESCRIPTIONS OF MINERALS. 


translucent ; H. = 1-2; G. = 6°48; contains 15:1 per cent. of chlo- 
rine and 84°9 of mercury. Spain. 

lIodie Mercury. Mercury iodide; reddish brown. Mexico. 

Magnolite. Mercury tellurate, in white, silky radiating tufts; 
Hg.O.Te. Magnolia District, Col. 

Barcenite. Gray to black, earthy lustre; H. =5°5; G. = 5°348; 
an antimonate containing 20°75 per cent. of mercury. Mexico. 


General Remarks.—The following are the regions of the principal 
mines of mercury. At Idria, in Austria (discovered in 1497), where 
the ore is a dark bituminous cinnabar distributed through a blackish 
shale or slate, containing some native mercury ; at Almaden, in Spain, 
near the frontier of Estremadura, in the province of La Mancha, in 
argillaceous beds and grit rock, which are intersected by dikes of 
‘‘ black porphyry” and granite—mines mentioned by Pliny as afford- 
ing vermilion to the Greeks, 700 years before the Christian era; in 
the Palatinate on the Rhine; in Hungary ; Sweden; France; Ripa, 
in Tuscany ; region of the Don, in Russia; in Shensi, in China; at 
Arqueros, in Chili; at Huanca Velica, and some other points in Peru; 
at St. Onofre and other places in Mexico; in California. 

The most noted of the California mines, New Almaden, is situated 
in Mine Hill, Santa Clara Co., south of San Francisco. The rocks 
are altered Cretaceous slates, talcose in part, with beds of serpentine 
either side, and associated also with beds of jasper or siliceous slate. 
The New Idria mine is in Fresno Co., in the Mt. Diablo Range, and 
was discovered in 1855. The rocks are more or less altered silico- 
argillaceous and siliceous slates and sandstones, and the cinnabar is 
distributed irregularly through them ;"between this and the Aurora 
Mine on San Carlos (the highest peak of the Diablo Range, 4977 feet), 
there is much serpentine (in which is chromic iron) and siliceous rock 
or slate. In Napa Valley, Napa Co., north of San Francisco, there 
are other valuable mines situated in rocks closely similar, as Whitney 
states, to those affording quicksilver at New Almaden. They are in 
a serpentine belt, the cinnabar being in some places in the serpentine, 
but mostly in the peculiar siliceous rock associated with it. Native 
mercury occurs with the cinnabar. There are mines also in Lake Co. 

The product of the California mines of mercury in 1874 was 34,254 
flasks (a flask in California = 764 Ibs), or over 2,600,000 lbs.; in 1881, 
60,851 flasks; in 1884, 31,918 flasks. About two thirds of the amount 
in 1884 was from the New Almaden mine. The yield of the Almaden 
mine, Spain, in 1884, was about 43,100 flasks, and that of the Idria 
mine, Austria, 18,000. The other foreign mines produce but little. 
The pape in 1884 was 20 to 35 dollars per flask, or 34 to 46 cents per 
pound, 


COPPER. 


Copper occurs native; also combined with oxygen, sul- 
phur, selenium, arsenic, antimony, chlorine; and as carbon- 
ate, phosphate, arsenate, nitrate, sulphate, vanadate, and 
silicate. The ores of copper vary in specific gravity from 
3°5 to 8°5, and seldom exceed 4 in hardness. 


COPPER. 145 


Native Copper. 

Isometric. In octahedral, dodecahedral, and other 
forms, often much distorted ; no cleavage apparent. Also 
in plates or masses, and in large or small arborescent and 
filiform shapes, consisting usually of a string of crystals. 

Color copper-red. Ductile and malleable. H. = 25-3. 
G. = 8°8-8:95; when pure 8:91-8:95. 

Often contains a little disseminated silver. B.B. fuses 
readily, and, on cooling, covered with the black oxide. 
Dissolves in nitric acid, and produces a deep azure-blue 
solution on the addition of ammonia. Fuses at 1930° F. 

Obs. Native copper accompanies ores of copper, and usually 
occurs in the vicinity of dikes of igneous rocks. 

Siberia, Cornwall, and Brazil are noted for the native 
copper they have produced. A mass, supposed to be from 
Bahia, now at Lisbon, weighs 2616 pounds. South of Lake 
Superior about Portage Lake on Keweenaw Point, and also, 
less abundantly, on the Ontonagon River, and at some other 
points in that region, native copper occurs mostly in veins 
in trap, and also in the enclosing sandstone. A mass 
weighing 3704 Ibs. has been taken from thence to Washing- 
ton City ; it is the same that was figured by Schoolcraft, in 
the American Journal of Science, volume iil., p. 201. One 
large mass was quarried out in the ‘Cliff Mine,” whose 
weight has been estimated at 200 tons. It was 40 feet long, 
6 feet deep, and averaged 6 inches in thickness. This cop- 
per contains, intimately mixed with it, about 3, per cent. 
of silver. Besides this, perfectly pure silver, in strings, 
masses, and grains, is often disseminated through the cop- 

er, and some masses, when polished, appear sprinkled with 
arge white spots of silver, ‘‘resembling a porphyry with its 
feldspar crystals.” Crystals of native copper are also found 
penetrating masses of prehnite and analcite in the trap rock. 
This mixture of copper and silver cannot be imitated by 
art, as the two metals form an alloy when melted together. 
It is probable that the separation in the rocks is due to 
the cooling from fusion being so extremely gradual as to 
allow the two metals to solidify separately, at their respec- 
tive temperatures of solidification—the trap being an igneous 
rock, and ages often elapsing, as is well known, during the 
cooling of a bed of lava when covered from the air. Native 
copper occurs sparingly on St. Ignace and Michipicoten 
Islands, Lake Superior. 

10 


146 DESCRIPTIONS OF MINERALS. 


Small specimens of native copper have been found in the 
States of New Jersey, Connecticut, and Massachusetts, 
where the Triassic formation occurs. One mass from near 
Somerville, N. J., weighs 78 pounds, and is said originally 
to have weighed 128 pounds. Within a few miles to the 
north of New Haven, Conn., one mass of 90 pounds, and 
another of 200, besides other smaller, have been found in 
the drift, all of which came from veins in the trap or asso- 
ciated Triassic sandstone. 

Native copper occurs also in South Australia ; it is stated 
that a single train from the Moonta Mine carried away at 
one time forty tons of native copper. 


SULPHIDES, SELENIDES, ARSENIDES. 
Chalcocite.—Copper Glance. Vitreous Copper Ore. Redruthite. 


Orthorhombic; 7: = 119° 35’. Cleavage parallel to J, 
but indistinct, Also in compound crystals 


like aragonite. Often massive. 
fee Color and streak blackish lead-gray ; 


often tarnished blue or green. Streak 
\$ sometimes shining. H. = 25-3. G.= 
55-58, 
Composition. Cu,S = Sulphur 20°2, 
¥ copper 79°3=100. B.B.on charcoal gives 
\ off fumes of sulphur, fuses easily in the 
XX exterior flame; and after the sulphur is 
driven off, a globule of copper remains. 
Dissolves in heated nitric acid, with a pre- 
cipitation of the sulphur. 

Diff. Resembles argentite, but is not sectile, and affords 
different results B.B, The solution in nitric acid covers 
an iron plate (or knife-blade) with copper, while a similar 
solution of the silver ore covers a copper plate with silver. 

Obs. Occurs with other copper ores in beds and veins, 
At Cornwall, splendid crystallizations; also in Siberia; 
Hesse; Saxony; the Banat; Chili, etc. 

In the United States, a vein formerly affording fine crys- 
tallizations occurs at Bristol, Ct. Ozther localities are at 
Wolcottville, Simsbury, and Cheshire, Ct.; at Schuyler’s 
Mines, and elsewhere, N. J.; in the U.S. copper-mine dis- 
trict, Blue Ridge, Orange County, Va.; between New 
Market and Taneytown, Md.; and sparingly at the copper 


COPPER. 147 


mines of Michigan and the Western States; also at some 
mines north of Lake Huron; in the San Juan and other 
mining regions in Colorado; in New Mexico, in Socorro and 
Grant Cos.; in Arizona; at the Bruce Mines, Lake Huron, 
and at Prince’s Mine, Spar Island, and on Michipicoten 
Island, Lake Superior. 


Covellite, or Blue Copper. Massive; dull blue-black; the composi- 
tion CuS; G. = 3'8; contains 66°5 per cent of copper. 
Harrisite. Chalcocite with cubic cleavage. Canton Mine, Ga. 


Chalcopyrite.—Copper Pyrites. Copper.and-Iron Sulphide. 


Tetragonal; 1 A\ 1=109° 53’, and 108° 40’. Crystals 
tetrahedral or octahedral; sometimes 
compound. Cleavage indistinct. Also 
massive, and of various imitative 
shapes. 

Color brass-yellow, often tarnished 
deep yellow, and also iridescent. 
Streak unmetallic, greenish black, 
and but little shining. H. = 3°5-4, 
G. = 4:15-4'3. 

Composition. CuFeS, = Sulphur | 
34°9, copper 34°6, iron 30°55 =100. Fuses B.B. to a mag- 
netic globule; gives sulphur fumes on charcoal. With soda 
on charcoal,a globule of metallic iron with copper. The 
usual efiect with nitric acid. 

Diff. Resembles native gold in color, and also pyrite. 
Distinguished from gold by crumbling under a knife, instead 
of separating in slices; and from pyrite in its deeper yellow 
color, and in yielding easily to the point of a knife, instead 
of striking fire with a steel. 

Obs. Occurs in veins intersecting gneiss and other meta- 
morphic rocks; also in those connected with eruptive rocks; 
and sometimes in cavities or veins in ordinary stratified 
rocks. Usually associated with pyrite, and often with galen- 
ite, blende, and copper carbonates. The copper of Fahlun, 
Sweden, is obtained mostly from this ore, where it occurs 
with serpentine in gneiss. Other mines of this ore are in 
the Hartz, near Goslar; in the Banat, Hungary, Thuringia, 
etc. ‘lhe Cornwall ore is mostly of this kind. As prepared 
for sale at Redruth it rarely yields 12 per cent., and gene- 
rally only 7 or 8, and occasionally as little as 3 to 4 per cent. 





148 DESCRIPTIONS OF MINERALS. 


of metal; ‘‘6} per cent. of metal may be considered an 
average of the produce of the total quantity of ore sold.” 
(Phillips, 1874. : Such poverty of ore is only made up by 
its facility of transport, the moderate expense of fuel, or 
the convenience of smelting. Its richness may generally 
be judged of from the color: if of a fine yellow hue, and 
yielding readily to the hammer, it is a good ore; but if hard 
and pale yellow it contains much pyrite, and is of poor 
quality. 

In the U. States it occurs at Ely and Strafford, Vt.; at 
Shrewsbury, Corinth, Waterbury, Vt.; also in New Hamp- 
shire, Maine, Massachusetts, and Connecticut; at the An- 
cram lead mine, N. Y.; also near Rossie, and at Wurtz- 
boro’, N. Y.; at Morgantown, Pa.; at the Phenix copper 
mines, Fauquier Co., and at the Walton gold mine, Lu- 
zerne Co., Va.; Liberty and New London in Frederick 
Co., at the Patapsco mines near Sykesville, Md.; in David- 
son and Guilford Cos., N.C. In Michigan, where native 
copper is so abundant, a rare ore; occurs at Presqu’isle, and 
at Mineral Point, in Wisconsin, where it is the predomi- 
nating ore; in Polk Co., at the Hiwassee mines, Tenn.; in 
the San Juan mining region, Col.; in Lander OCo., and 
elswhere, Nev.; in New Mexico; Arizona; Idaho; Utah; at 
Copperopolis, Calaveras Co., Cal.; also at the Bruce and 
other mines on Lake Huron; and Michipicoten Islands, in 
Lake Superior. 


Cubanite is a copper-and iron sulphide, containing Sulphur 39 0, 
iron 38°0, copper 19°8, silica 2°3 = 99°12, Cuba. 


Bornite.—Erubescite. Variegated Copper Pyrites. 


Isometric; in octahedrons and dodecahedrons. Cleay- 
age octahedral in traces. Also massive. 

Color between copper-red and pinchbeck-brown; but 
tarnishes rapidly on exposure. Streak < pale Spek black 
and but slightly shining. Brittle H.=3. G. = 4:°4-5°5. 

Composition. Ou,KeS, = Sulphur 28°6, copper 55°58, 
iron 16°36; but varies much. ‘The ore of Bristol, Ct., af- 
forded Sulphur 25°83, copper 61°79, iron 11°77 = 99°39. ° 

B.B. on charcoal fuses to a brittle globule attractable by 
the magnet; dissolves in nitric acid, with separation of 
sulphur. 

Diff. Distinguished from the preceding by its pale red- 


COPPER. 149 


dish-yellow color, and its rapidly tarnishing and becoming 
of bluish and reddish shades of color, the quality to which 
ee name erubescite, from the Latin word for to dlush, al- 
udes. 

Obs. Occurs, with other copper ores, in granitic and al- 
lied rocks, and also in stratified formations. The mines of 
Cornwall have afforded crystallized specimens, and it is 
there called, from its color, ‘‘horse-flesh ore.” Other for- 
eign localities of massive varieties are Ross Island, Killar- 
ney, Ireland; Norway, Hessia, Silesia, Siberia, and the 
Banat. 

Hine crystallizations were formerly obtained at the Bris- 
tol copper mine, Ct., in granite; and also in red sandstone, 
at Cheshire, in the same State, with malachite and barite. 
Massive varieties occur at the New Jersey mines, and in 
Pennsylvania. 


Crookesite. Copper sclenide containing 17°25 per cent. of thallium, 
and a little silver. Norway. 

Domeykite. White to pinchbeck-brown metallic; H. = 3-3°5; G@. = 
%-7'5; copper arsenide, Cu;As. = Arsenic 28°3, copper 71°7 = 100. 
Chili; Portage Lake; Michipicoten Island, L. Superior. Algodonite is 
CucsAs:,, Whitneyite is CusAs:, and is from Houghton Co., Mich.; 
Sonora. 

Berzelianite is a copper selenide; Hucairite, a copper-and-silver 
selenide. 


SULPHARSENITES, SULPHANTIMONITES, AND SULPHOBISMUTHITES. 


These species include—of SULPHARSENITES: Hnargite, Binnite, 
Tennantite, Lautite, Clarite, Xanthoconite ; of SULPHANTIMONITES : 
Tetrahedrite, Polybasite (p. 133), Chalcostibite, Guejarite, Stylotypite, 
Bournonite (Wheel Ore), Famatiniie ; of SULPHOBISMUTHITES: A?k- 
tnite (p. 164), Hmplectite, Chiviatile, Wittichenite. 

Enargite. Orthorhombic; grayish iron-black; H. = 3; G. = 4:34 
4°45; never fibrous; contains 46-50 p. c. of copper. forococha, 
Peru; Chili (Guayacanite); Brewster’s gold mine, 8. C.; Morning 
Star mine, Alpine Co., Cal.; in Gilpin and San Juan Cos., Col. 

Famatinite, from Peru and Arg. Republic, is an antimonial enargite 
in composition; color grayish copper-red; G. = 4°57. 

Binnite. In isometric crystals. Valley of Binnen. 

Tennantite. In dodecahedrons; color and streak lead-gray to iron- 
black; contains some iron with the copper. Cornwall; Norway; Cap- 
elton, Quebec. 

Fredericite is a variety from Sweden, containing 2°87 p. c. of silver; 
and Sandbergerite, one containing zinc, from Peru. 


150 DESCRIPTIONS OF MINERALS. 


Tetrahedrite. Gray Copper. Fablerz. 


Isometric; in tetrahedral crystals. Steel-gray to blackish, 
and streak nearly the same, to brown and cherry-red. H. = 
3-4°5. G. = 4°7-5; but the mercuriferous, 5°1-5°6. 

Composition. 4CuS +8b,8,. Part of the copper often 
replaced by iron and zinc, and some- 
times by silver or mercury, and part 
4 of the antimony by arsenic, or rarely 
bismuth; the argentiferous (Frei- 
bergite) sometimes contains 30 p. ec. 
of silver, and the wmercuriferous 
(Schwatzite) 15 to 18 p. ¢. of mer- 
cury; a kind from Spain contained 
10 p. c. of platinum, and one from 
Hohenstein some gold; another 
(named Malinowskite) 9 to 13 p.c. of lead and 10 to 13 of | 
silver. ‘The Arkansas mineral afforded on analysis, Sul- 
phur 26°71, antimony 26°50, arsenic 1°02, copper 36°40, 
iron 1°89, zinc 4°20, silver 2°30 = 99:02. 

From Cornwall; Andreasberg, Hartz; Kremnitz, Hun- 
gary; Freiberg, Saxony; Kapnik, Transylvania; Dillen- 
burg, Nassau; Huallanca, Peru, at a height of 14,700 feet; 
Mexico, at Durango, etc.; Mariposa and Shasta Co., Cal.; 
Sheba and De Soto mines, Humboldt Co. and near Austin, 
Ney.; Heintzelman mine, Santa Rita mine, ete., Arizona; 
Socorro Co., New Mexico; Gilpin and Clear Summit, 
Hinsdale and San Juan Cos., Col., a common silver ore; 
Idaho; Utah; N. of Little Rock, Kellogg mines, Ark. 


Frigidite is a nickeliferous variety from the Apuan Alps. 

Chiviatite. Foliated massive; lead-gray; contains 60 p. c. of bis- 
muth. Peru. 

Wittichenite (Cupreous Bismuth). Orthorhombic, massive ; steel- 
gray; contains 40 to 50 p. c. of bismuth, and 30 to 35 of copper. 





OXIDES. CHLORIDES. 
Atacamite.—Copper Oxichloride. 


Orthorhombic; in rhombic prisms and other forms; also 
granular massive. Color green to blackish green. Lustre 
adamantine to vitreous. Streak apple-green. Translucent 
to subtranslucent. H.=3-35. G.=3:'76-3°9. Com- 
nosition, CuCl, + 3CuO0,H, = Chlorine 16°64, oxygen 11°25, 
copper 11°25, water 12°66 = 100. From the Atacama 


COPPER. 151 


desert, between Chili and Peru, and elsewhere in Chili; 
Bolivia; Vesuvius; Saxony; Spain; Cornwall; N. 8S. Wales. 


Cuprite.—Red Copper Ore. 


Isometric. In regular octahedrons, and modified forms 
of the same. Cleavage octahedral. Also massive, and 
sometimes earthy. Color deep red, of various shades. 


Streak brownish red. Lustre adamantine or submetallic; 
also earthy (¢v/e ore). Subtransparent to nearly opaque. 
Brittle. H.=—3°5-4. G. = 5:99; 5:85-6:15. 

Composition. Cu,O = Oxygen 11:2, copper 88°8. B.B. 
on charcoal, a globule of copper. Dissolves in nitric acid. 

Diff. Differs from cinnabar in not being volatile B.B.; 
from hematite in yielding a bead of copper on charcoal, 
and in copper reactions. 

Obs. Occurs with other copper ores in the Banat, Thu- 
ringia, Cornwall, at Chessy near Lyons, in Siberia, and 
Brazil. The octahedrons are often green, from a coating 
of malachite. In the U. States, occasionally crystallized 
and massive at Schuyler’s, Somerville, and the Flemington 
copper mines, N. J.; near New Brunswick, N. J.; at Bris- 
tol, Ct.; near Ladenton, Rockland Co., N. Y.; in the Lake 
Superior region; in Arizona; N. Mexico; Utah; Wyoming. 





Melaconite, or Black Copper. Oxide of copper, CuO; a black pow- 
der, and in dull black masses and botryoidal concretions, along with 
other copper ores. Abundant in some of the copper mines of the Mis- 
sissippi Valley, and yields 60 to 70 per cent.of copper. Results from 
the decomposition of the sulphides and other ores. At the Hiwassee 
Mine, Polk Co., Tennessee, it has been abundant. Formerly found 
of excellent quality in the Lake Superior copper region. 

Tenorite. A like oxide, occurring in black flexible, metallic scales 
on lavas. Vesuvius. -Aéedite is an oxichloride pseudomorph after 
tenorite. 

Friochaleite. A copper chloride. Vesuvius. 

Melanothallite. Copper chloride. Vesuvius, cruption of 1£70, 


152 DESCRIPTIONS OF MINERALS. 


SULPHATES, 'TUNGSTATES. 
Chalcanthite.—Blue Vitrio]. Sulphate of Copper. 


Triclinic. In oblique rhomboidal prisms. Also as an 
efflorescence or incrustation, and stalactitic. 

Color deep sky-blue. Streak uncolored. Subtransparent 
to translucent. Lustre vitreous. Soluble, taste nauseous 
and metallic. H. = 2-2°5. G. = 2°21. 

Composition. CuO,S+ 5 aq (or CuO +80, + 5 aq) = 
Sulphuric acid (or sulphur trioxide) 32:1, copper oxide 31°8, 
water 36°1. A polished plate of iron in solutions becomes 
covered with copper. 

Obs. Occurs with the sulphides of copper as a result of 
their decomposition, and is often in solution in the waters 
flowing from copper mines. In the Hartz; at Fahlun in 
Sweden; Rio Tinto mine, Spain; Copiapo, Chili; H1- 
wassee copper mine, ‘Tenn. ; - Canton. mine, Ga.; in Arizona. 

Blue vitriol is much used in dyeing, and in the printing 
of cotton and linen ; also for various other purposes in the 
arts. It has been employed to prevent dry rot, by steeping 
wood in its solution ; and it is a powerful preservative of 
animal substances, they remaining unaltered when imbued 
with it and dried. ‘ Afforded by the decomposition of chal- 
copyrite in the same manner as green vitriol from pyrite 3 
but it is manufactured for the arts chiefly from old sheath- 
ing-copper, copper turnings, and copper refinery scales. 

In Frederick Co., Md., blue vitriol is made from a black 
earth which is an impure oxide of copper with copper pyrites. 

In some mines, the solution of sulphate of copper is so 
abundant as to afford considerable copper, which is obtained 
by immersing clean iron in it, and is called copper of cemen- 
tation. At the copper springs of Wicklow, Ireland, about 
500 tons of iron were laid at one time in the pits; in about 
12 months the bars were dissolved, and every ton of iron 
yielded a ton and a half, and sometimes nearly two tons, of 
a precipitated reddish mud, each ton of which produced 16 
cwt. of pure copper. The Rio Tinto Mine in Spain is 
another where the sulphate in solution is thus utilized; the 
waters yield annually 1880 cwt. of copper, and consume 
2400 ewt. of iron. 


Anhydrous Copper Sulphates,—Dolerophanite. Monoclinic ; brown; 
Cu.0;8. Vesuvius. 


COPPER. 153 


Tydrocyanite, Orthorhombic ; green, brownish, sky-blue ; soluble. 
Vesuvius. 

Hydrous Copper Sulphates.—Brochantite. Orthorhombic, tabular ; 
color emerald-green; G. = 3°8-3'9. Urals; Cornwall; Mexico; Chili; 
Australia. Kyrisuvigiie and Konigite are the same. 

Langite. Orthorhombic; fine blue, greenish; G. = 8°48-3°5; Corn- 
wall. 

Cyanotrichite (Velvet Ore). Velvet like; smalt-blue to sky-blue. 
Moldawa. 

Arnimite. Monoclinic; green; Planitz, Bohemia. Herrengrundite 
(Urovdlgyite) is a similar copper sulphate, but contains some lime ; 
emerald-green. Hungary. 

Hydrous Copper-sodium Sulphate.—Krénkite. Azure-blue. Bolivia. 

Hydrous Copper-iron Sulphate.—Philippite. Azure-blue; astrin- 
gent. Chili. 

Anhydrous Oopper-zine Sulphate (?).—Serpierite. Orthorhombic, 
greenish, bluish. Laurium, Greece. 

Sulphato-chloride.—Connellite. Hexagonal; fine blue. Cornwall. 

Copper-potassium sulphato-chloride.—Chlorothionite. Bright blue ; 
soluble. Vesuvius. . 

Copper Tungstates.—Cuprotungstite. In yellowish-green crusts. 
Santiago, Chili. 


PHOSPHATES, ARSENATES, VANADATES, NITRATE. 


Olivenite.—Hydrous Copper Arsenate. 


Orthorhombic ; 7A J = 92° 30’. In prismatic crystals ; 
also fibrous, and granular massive. Olive-green, and of 
other greenish shades, to liver and wood-brown. Streak 
olive-green to brown. Subtransparent to opaque. Brittle. 
H.=3. G. = 4:13-4:38; fibrous, 3-9-4. 

Composition. Cu,O,As, (or 4CuO + As,O,) = Arsenic 
i gs 40°66, copper oxide 56°15, water 3°19 = 100. 

uses very easily, coloring the flame bluish green. B.B. 
fuses with deflagration, giving off arsenical fumes, and 
affords a brittle globule, which with soda yields metallic 
copper. 

Obs. From Cornwall, the Tyrol, Siberia, Chili; Tintic 
Dist., Utah. 


There are also the following salts of copper: 

Copper Arsenates,—Huchroite is bright emerald-green ; contains 33 
per cent. of arsenic acid, and 48 of copper oxide ; occurs in modified 
rhombic prisms ; H. = 8°75; G. = 3°39 ; from Libethen, in Hungary. 
Clinoclasite (Aphanesite) is of a dark verdigris green inclining to blue, 
and also dark blue; H. = 2°5-3; G. = 4°19-4°36; contains 62°7 per 
cent. of copper oxide; from Cornwall. SHrinite occurs in emerald- 
green mammillated coatings; H. = 45-5; G. = 4°04; contains 59°4 
per cent. of copper oxide ; from Limerick, Ireland. Jzroconite varies 


154 DESCRIPTIONS OF MINERALS. 


from sky-blue to verdigris-green ; occurs in rhombic prisms, some- 
times an inch broad; H. = 2-2°5; G. = 2°88-298. Chalcophyilite 
(Copper mica) is remarkable for its thin foliated or mica-like structure; 
color emerald or grass-green ; H. = 2; G. = 2°48-2°66 ; contains 58 
per cent. of copper oxide; from Cornwall and Hungary. Tyrolite 
(Copper froth) is another arsenate of a pale apple-green and verdigris- 
green color, having a perfect cleavage ; contains 43°9 per cent. of 
copper oxide ; from Hungary, Siberia, the Tyrol, and Derbyshire. 
Conichaicite, Cornwallite, Chiorotile, Chenevivite, are names of other 
copper arsenates. These different arsenates of copper give an allia- 
ceous odor when heated on charcoal before the blowpipe. 

Mixite, A hydrous arsenate containing 13 per cent. of oxide of bis- 
muth (Bi,O;), emerald to bluish green ; prismatic. Joachimstahl. 

Leucochaicite. A white, silky, hydrous copper arsenate. Spessart, 
Germany. 

Pee Re, Tetragonal ; bluish green; copper arsenite. Copiapo, 

ili. 

Chalcomenite. A hydrous copper selenite, in bright blue crystals. 
Mendoza, 8S. A. 

Copper Phosphates.—Pseudomalachite (Phosphochalcite, Hhlite, Di- 
hydrite). In very-oblique crystals, or massive and incrusting ; of an 
emerald or blackish green color; H. = 45-5; G. = 4-4°4; contains 
64 to 70 per cent. of copper oxide ; from near Bonn, on the Rhine, and 
also from Hungary. JLibethenite has a dark or olive-green color, and 
occurs in crystals, usually octahedral in aspect, and massive; H. = 
4; G. = 3°6-3'8 ; contains 66°5 per cent. of oxide of copper; from 
Hungary and Cornwall. Other copper phosphates are Veszelyite 
(hydrous arseno-phosphate), Zagilite, Isoclasite. Torberniteis a copper- 
uranium phosphate (p. 170). These phosphates give no fumes before 
the blowpipe, and react for phosphoric acid. 

Copper Vanadates.— Volborthite is a copper-barium-calcium vanadate 
from the Urals; Mottrammite and Psittacinite, copper-lead vanadates, 
the former from England, the latter from gold-mines in Silver Star 
district, Montana. 

Thrombolite, an antimonate. Stetefeldite, Partzite, antimonite. 

Rivotite. Yellowish-green copper antimonate and carbonate. 

Gerhardtite. Copper nitrate in orthorhombic crystals ; dark green; 
insoluble. United Verde Mines, Jerome, Ariz, 


CARBONATES, 
Malachite.—Green Copper Carbonate. 


Monoclinic. Usual in incrustations, with a smooth tube- 
rose, botryoidal, or stalactitic surface ; structure finely and 
firmly fibrous. Also earthy. 

Color light green, streak paler. Usually nearly opaque ; 
crystals translucent. Lustre of crystals adamantine inclin- 
ing to vitreous ; but fibrous incrustations silky on a cross 
fracture. Earthy varieties dull. H.=3°5-4. G. = 3-7-4, 

Composition. Cu,O,C-+ H,O (or 2Cu0 + CO, + H,0) 


COPPER. 155 


= Carbon dioxide (or carbonic acid) 19°9, copper oxide 
71°9, water 8°2=100. MDissolves with effervescence in 
nitric acid. 

B.B. decrepitates and blackens, colors the flame green, 
and becomes partly a black scoria. With borax, fuses to a 
deep-green globule, and ultimately affords a bead of copper. 

Diff. Readily distinguished by its copper-green color and 
its associations with copper ores. Resembles a siliceous 
ore of copper, chrysocolla, a common ore in the mines of 
the Mississippi Valley ; but it is distinguished by its com- 
plete solution and effervescence in nitric acid. The color 
also is not the bluish green of chrysocolla. 

Obs. Usually accompanies other ores of copper, and 
forms incrustations, which, when thick, have the colors 
banded and delicate in their shades and blending. Perfect 
crystals are quite rare. The mines of Siberia, at Nischne 
Tagilsk, have afforded great quantities of this ore. A mass, 
partly disclosed, measured at top 9 feet by 18; and the 
_ portion uncovered contained at least half a million pounds 
of pure malachite. Other noted foreign localities are 
Chessy, in France; Sandlodge, in Shetland ; Schwatz in 
the Tyrol ; Cornwall ; the Island of Cuba; Serro do Bembe, 
west coast of Africa; copper mines of Australia; Chili. 

Occurs in Cheshire, Ct.; Morgantown, Perkiomen, and 
Phoenixville, Pa.; Schuyler’s Mine, and the New Brunswick 
copper mine, N. J.; between Newmarket and Taneytown 
in the Catoctin Mountains, Md.; in the Blue Ridge, Pa., 
near Nicholson’s Gap; also in Tintic district, Utah ; Cal- 
averas Co., Cal.; Colorado; Arizona; Idaho. At Mineral 
Point, Wisconsin, a bluish silico-carbonate of copper occurs, 
which is for the most part chrysocolla, or a mixture of this 
mineral with the carbonate. 

Receives a high polish and is used for tables, mantel- 
pieces, vases; and also ear-rings, snuff-boxes, and various 
ornamental articles. Too soft to be much prized in jewelry. 
The tables, vases, and other articles made of it have great 
beauty. 

Malachite is sometimes passed off in jewelry as turquois, 
though easily distinguished by its shade of color and much 
inferior hardness. It is a valuable ore when abundant; but 
it is seldom smelted alone, because the metal is liable to es- 
cape with the liberated volatile ingredient. 


156 DESCRIPTIONS OF MINERALS. 


Azurite.—Blue Copper Carbonate. Blue Malachite. 


Monoclinic. In modified oblique rhombic prisms, the 
crystals rather short and stout; 
lateral cleavage perfect. Also 
massive. Often earthy. 

Color deep blue, azure-blue, 
Berlin-blue. Transparent to nearly 
opaque. Streak bluish. Lustre 
vitreous, almost adamantine. 
Brittle H.=3%5-45. G= 
3°5-3°83. 

Composition. Cu,O,C,+ H,O 
(or 3CuO + 2C0, + H,O) = Carbon dioxide 25°6, copper 
oxide 69°2, water 5:2. B.B. and in acids like the preced- 
ing. 

Obs. Accompanies other ores of copper. Chessy, France, 
has afforded fine crystals; found also in Siberia; the Banat; 
near Redruth in Cornwall; at Phoenixville, Pa.,in crystals; 
in Wisconsin near Mineral Point; as incrustations, and 
rarely as crystals, near New Brunswick, N. J.; near Nichol- 
son’s Gap, in the Blue Ridge, Pa. 

When abundant, a valuable ore of copper. Makes a poor 
pigment, as it is liable to turn green. | 





Aurichalcite (Buratite). A hydrous copper-zine carbonate, or a 
cuprous hydrozincite; pale green to sky-blue; Altai; Retzbanya ; 
ae, in France; Tyrol; pain; Leadhills in Scotland; Lancaster, 

a. 


SILICATES. 
Dioptase.—Copper Silicate. 


Rhombohedral; RA R=126° 24’. Occurs in six-sided 
prisms with rhombohedral terminations. Color emerald- 
green. Lustre vitreous. ‘Transparent to nearly opaque. 
H.=5. G. =3°28-3°35. ; 

Composition. CuH,O,Si = Silica 38:1, copper oxide 50°4, 
water 11°5=100. B.B. with soda on charcoal yields copper, 
and this, with its hardness, distinguishes it from the spe- 
cies it resembles. 

Obs. From the Khirgeez Steppes of Siberia; Chili; near 
Clifton, Arizona. 


COPPER. 157 


Chrysocolla.—_Hydrous Copper Silicate. 


Usually as incrustations; botryoidal and massive; in thin 
seams and stains; no fibrous or granular structure apparent, 
nor any appearance of crystallization. 

Color clear bluish green. Lustre of surface of incrusta- 
tions s smoothly shining; ; alsoearthy. Translucent to opaque. 

=2-4. G.=2-2: 
C Composition. CuO Si+2 aq (or ronmsiaies +2aq) = 
Silica 34°2, copper oxide 45°3, water 20°5 = 100. 


SIBERIAN, NEW JERSEY. 

Von Kobell. Berthier. Bowen. Beck. 
<Pxide OL copper... 40°0 .........». B51 0.0) 4572 ~ «ef 42°86 
POR eee, e, . o. Ory hala We vs aor’ BG°45: nee BCS. e400 
Vio 2 a anne: Er 28 'Dicv ce k i Oss W eo 
Carbonic acid ..... 2 RE ee aoe —— nee oe eee 
Oxide of iron...... SLs hts hb oh iee ped — .... —.... 14 


Varies much in the proportion of its constituents, as it is 
not crystallized. Prlarite is an aluminous variety. 

B.B. blackens in the inner flame, and yields water 
without melting. With soda on charcoal yields a globule 
of copper. 

Diff. Distinguished from green malachite as stated under 
that species. 

Obs. Accompanies other copper ores in Cornwall, Hun- 
gary, the Tyrol, Siberia, Thuringia, ete. Abundant in 
Chili at various mines; in Wisconsin and Missouri worked 
for copper. Formerly taken for green malachite. Occurs 
at the Somerville and Schuyler’s mines, N. J.; at Mor- 
gantown, Pa.; Cheshire, Ct.; Utah, Colorado; California ; 
N.S. Wales. 

This ore in the pure state affords 30 per cent. of copper; 
but as it occurs in the rock will hardly yield one-third this 
amount. Still, when abundant, as it appears to be in the 
Mississippi Valley, it is a valuable ore. 


Neocianite is a blue monoclinic mineral, supposed to be an anhy- 
drous copper silicate. Vesuvius. 


General Remarks.—The most valuable sources of copper for the arts 
are native copper, chalcopyrite or ‘‘ yellow copper ore,” chalcocite or 
“copper glance,” dbornite or ‘* variegated copper ore, ” malachite or 
“* grecn carbonate of copper,” chrysocolla or ‘ ‘ silicate,” cuprite or ‘‘red 
oxide of copper;” and occasionally ‘* black copper.’ 

The principal copper regions, exclusive of the American, are as fol- 
lows: The Cornwall and Devon, England, where the ore is mostly 


158 DESCRIPTIONS OF MINERALS. 


chalcopyrite; about Mansfeld, in Prussia, having the ore distributed 
through a bed of red shale in the Permian (Kupferschiefer), about 
eighteen inches thick, making about 24 per cent. of the bed; the Urals 
on their western slope, in the Permian, as in Mansfeld; also more pro- 
ductively on the eastern side of the Urals, at the Nischne Tagilsk and 
Bogoslowskoi mines, in Silurian limestone where traversed by eruptive 
rocks, and at the Gumeschewskoi mine, in argillaceous shale, the ore 
chiefly malachite and cuprite; in France, at Chessy, near Lyons, of 
malachite and azurite, now of little value; in Norway, at Alten, and 
in Sweden, at Fahlun; in Hungary, at Schemnitz, Kremnitz, Kapnik, 
and the Banat; in Italy, at Monte Catini; in Spain, in the province of 
Huelva, where is the Rio Tinto mine, which affords chalcopyrite, and 
also the sulphate (p. 152); in Portugal, at San Domingo, near the 
mouth of the Guadiana; in Algeria, Turkey, China, Japan, Cape of 
Good Hope; in South Australia, where are three prominent mines, 
the Burra, Wallaroo, and Moonta, their yield in 1875, £451,500; New 
South Wales, the largest mine at Cobar, 500 m. W. of Sydney. 

In South America, in Chili, in the vicinity of Copiapo, and less 
abundantly at other places to the south; in Bolivia, also in Peru, and 
the Argentine Republic, but not much developed. In Cuba, but much 
less productive than formerly. 

In Eastern North America some copper has been afforded by the 
Triassic of New Jersey and the Connecticut Valley, but there are no 
producing mines. At Ely, Vt., and Milan, N. H., veins of chalcopy- 
rite are worked. The chief sources of copper are the veins of Northern 
Michigan, where the veins are connected with trap-dikes intersecting 
a Cambrian red sandstone, as stated on page 145. ‘The Cliff mine was 
onc of the earliest opened, and there the largest masses of native copper 
have been found. Other veins have since been opened in various parts 
of the region, at Eagle Harbor, Eagle River, Grand Marais, Lac La 
Belle, Agate Harbor, Torch Lake, on the Ontonagon, in the Porcupine 
Mountains, and elsewhere. In Tennessee, at the Hiwassee mines, but 
work suspended; in Virginia, at Tolersville; in North Carolina, at Ore 
Knob; in Georgia, the Tallapoosa mines; in Missouri, in Sainte Gene- 
vieve Co., from one or two levels in the Lower Silurian limestone; also 
north of Lakes Superior and Huron, and on Isle Royale and the Michi- 
picoten Islands, in Lake Superior, but not now productive; in New- 
foundland valuable mines at Tilt Cove and Betts Cove mines, and in 
the vicinity of Capelton. 

In Western North America, in Arizona, there are large veins of 
copper north of the Gila, on the borders of New Mexico, in the Clif- 
ton, Warren, and Globe districts; in New Mexico, in the Nacimiento 
Mts., the Sandia Mts., cast of Albuquerque, the Andreas Mts., and 
elsewhere; in Colorado, at the towns of Central, Black Hawk, and 
Nevada in Gilpin Co.; in the San Juan Mts., north of Cafion City; in 
Utah, in the Tintic district; in Montana, near Butte City; also in Idaho, 
Wyoming, and Nevada, but mostly awaiting development; in Cali- 
fornia, at Coppceropolis (formerly worked); at Spenceville in Nevada 
Co. 

The total production of copper in the United States in 1845 was 100 
long tons, 12 of it from the Lake Superior region; in 1855, 8000, with 
2593 from L. 8.; in 1865, 8500, with 6410 from L. §.; in 1875, 18,000, 


COPPER. 159 


with 16,089 from L. §.; in 1880, 27,000, with 22,204 from L. 8.; in 
1885, 74,000, with 32,210 from L.S., 30,270 from Montana, 10,135 
from Arizona, and 1435 from other States. The world’s production 
for 1880 is estimated at 153,057 tons, and for 1885 at 221,715tons. Of 
the latter, Chili produced 38,500 tons; Spain and Portugal about 
46,000; Germany about 15,000; Australia, 11,400; Japan, 10,000; 
Southern Africa, 5450; Sweden, 5000; Venezuela, 4111; England 
about 3000, and other countries about 9000 tons. 

In 1884, the Calumet and Hecla mine, Michigan, yielded 40,473,585 
pounds; the Quincy, 5,680,087; the Osceola, 4,247,630; the Franklin, 
3,748,652; the Atlantic, 3,163,585; all the other L. Superior mines 
about 12,000,000 pounds. 

The metal copper was known in the earliest periods and was used 
mostly alloyed with tin, forming bronze. The mines of Nubia and 
Ethiopia are believed to have produced a great part of the copper of 
the early Egyptians. Eubcea and Cyprus are also mentioned as afford- 
ing this metal to the Greeks. It was employed for cutting instru- 
ments and weapons, as well as for utensils; and bronze chisels are at 
this day found at the Egyptian stone-quarries, that were ouce em- 
ployed in quarrying. This bronze (chalkos of the Greeks, and @s of 
the Romans) consisted of about 5 parts of copper to 1 of tin, a propor- 
tion which produces an alloy of maximum hardness. Nearly the 
same material was used in early times over Europe; and weapons and 
tools have been found consisting of copper, edged with iron, indicating 
the scarcity of the latter metal. Similar weapons have also been 
found in Britain; yet it is certain that iron and steel were well known 
to the Romans and later Greeks, and to some extent used for warlike 
weapons and cutlery. Bronze is hardened by hammering or pres- 
sure. 

Copper knives, axes, chisels, spear-heads, bracelets, etc., have been 
found in the Indian mounds of Wisconsin, Illinois, and the neighbor- 
ing States; and there is evidence that the Indians, besides using drift 
masses of copper, knew of the copper veins of Northern Michigan, and 
worked them, especially in the Ontonagon region, where their tools 
and excavations have been discovered. 

Copper at the present day is very various in its applications in the 
arts. It is largely employed for utensils, for the sheathing of ships, 
and for coinage. Alloyed with zinc it constitutes brass, and with tin 
it forms bell-metal as well as bronze. 

Brass consists of copper 65 per cent., zinc 35; with 53°5 per cent. of 
zinc the alloy is silver-white; casting brass of 65-72 copper, 385-28 zinc; 
o-molu or Dutch metal, of 70-85 copper, 15-25 zinc, with 0°3 of each, 
lead and tin; brass for lathe-work of 60-70 copper, 28-88 zinc, 2 lead; 
Muntz metal, for the sheathing of ships, 60 copper, 89 zinc, 1 lead; 
spelter solder for brass, copper 50, zinc 50. 

Bronze for medals consists of copper 93, tin 7; for speculum metal, 
copper 60, tin 80, arsenic 10; for casting bronze, copper 82-83, tin 1-3, 
zine 17-18; for gun-metal, copper 85-92, tin 8-15; for bell-metal, cop- 
per 65-80, tin 20-35, antimony 0-2; antique bronze, copper 67-95, tin 
8-15, lead 0-1, zinc 0-15. 

Lord Rosse used for the speculum of his great telescope 126 parts 
of copper to 574 parts of tin. The brothers Keller, celebrated for 


160 DESCRIPTIONS OF MINERALS. 


their statue castings, used a metal consisting of 91°4 per cent. of cop- 
per, 5°53 of zinc, 1°7 of tin, and 1°37 of lead. An equestrian statue 
of Louis XIV., 21 feet high, and weighing 53,263 French pounds, was 
cast by them in 1699, ata single jet. 

An alloy of copper 90, and aluminium 10, is sometimes used in place 
of bronze. 


LEAD. 


Lead occurs rarely native ; generally in combination with 
sulphur; with arsenic, tellurium, selenium, and in the con- 
dition of sulphate, carbonate, phosphate and arsenate, 
chromate and molybdate. 

The ores of lead vary in specific gravity from 5*5-8°2, 
They are soft, the hardness of the species with metallic lus- 
tre not exceeding 3, and others not over 4. ‘They are 
easily fusible before the blowpipe (excepting plumbo- 
resinite) ; and with soda on charcoal (and often alone), 
malleable lead may be obtained. ‘The lead often passes off 
in yellow fumes, when the mineral is heated on charcoal 
in the outer flame, or it covers the charcoal with a yellow 
coating. 

Native Lead. 

A rare mineral, occurring in thin laminz or globules, 
G. = 11°35. Said to have been seen in the lava of Madeira ; 
at Alston in Cumberland with galena; in the County of 
Kerry, Ireland ; in an argillaceous rock at Carthagena ; at 
Camp Creek, Montana; Jay Gould Mine, Idaho, in galena, 


SuLpPnHipEs, SELENIDES, TELLURIDES. 
Galenite.—Galena. Lead Sulphide. 


Isometric. Cleavage cubic, eminent, and very easily ob- 
tained. Also coarse or fine granular ; rarely fibrous. 


1. 2. 





Color and streak lead-gray. Lustre shining metallic. 
Fragile.  H. = 2°5. G. ='7-25-7'35 ;. 6932757 ee 
Composition. PbS = Sulphur 13°4, lead 86°6 = 100, 


LEAD. 161 


Often contains some silver sulphide, and is then argentifer- 
ous galena ; at times zinc sulphide is present. The ore of 
veins intersecting crystalline metamorphic rocks is most 
likely to be argentiferous. ‘The proportion of silver varies 
ereatly. In Europe, when it contains only 7 or 8 ounces 
to the ton it is worked for the silver. The galenite of the 
Hartz afords -03 to °05 per cent. of silver; the English 02 
to 03 per cent.; that of Leadhills, Scotland, :03 to :06; 
that of Pike’s Peak, Colorado, :05 to °06; that of Arkan- 
sas, ‘03 to 05; that of Middletown, Ct., °15 to °20; that 
of Roxbury, Ct., 1°85; that of Monroe, Ct., 3:0; while 
that of Missouri afforded Dr. Litton only -0012 to :0027 
per cent. A little antimony or cadmium is sometimes 
present. 

B.B. on charcoal, it decrepitates unless heated with cau- 
tion, and fuses, giving off sulphur, coats the coal yellow, 
and finally yields a globule of lead. 

Diff. Resembles some silver and copper ores in color, 
but its cubical cleavage, or granular structure when mas- 
sive, will usually distinguish it. Its reactions before the 
blowpipe show it to be a lead ore, and a sulphide. 

Obs. Occurs in granite, limestone, argillaceous and sand- 
stone rocks, and is often associated with ores of zinc, silver, 
and copper. Quartz, barite, or calcite is generally the 
gangue of the ore; also at times fluor spar. The rich lead- 
mines of Derbyshire, and the northern districts of England, 
occur in the Subcarboniferous lmestone; and the same 
rock contains the valuable deposits of Bleiberg, in Austria, 
and the neighboring deposits of Carinthia. The ore of 
Cornwall is in true veins intersecting slates and is argentif- 
erous. At Freiberg in Saxony, it occupies veins in gneiss; 
in the Upper Hartz, and at Przibram in Bohemia, it 
traverses clay slate of Lower Silurian age; at Sahla, Sweden, 
it occurs in crystalline limestone. ‘There are other valua- 
ble beds of galena, in France at Poullaouen and Huelgoet, 
Brittany, and at Villefort, Department of Lozére; in Spain 
in the granite and argillyte hills of Linares, in Catalonia, 
Granada, and elsewhere; in Savoy; in Netherlands at 
Vedrin, not far from Namur; in Bohemia, southwest of 
Prague; in Joachimstahl, where the ore is worked princi- 
pally for its silver ; in Siberia in the Daouria Mountains in 
limestone, argentiferous and worked for the silver. 

Deposits of this ore occur in limestone, in the States of 

11 


162 DESCRIPTIONS OF MINERALS. 


Missouri, Illinois, Iowa, and Wisconsin ; argillaceous iron 
ore, pyrite, calamine and smithsonite (‘‘dry bone” of the 
miners), blende (‘‘ black-jack”), carbonate of lead or cerus- 
site, and barite or heavy spar, are the most common asso- 
ciated minerals; and less abundantly chalcopyrite and 
malachite, ores of copper ; also occasionally the lead ores, 
anglesite and pyromorphite; and in the Mine La Motte 
region, black cobalt, and linneite, an ore of nickel. 

Lead ore was first noticed in Missouri in 1700 and 1701. 
In 1720 the mines were rediscovered by Francis Renault 
and M. La Motte; and the La Motte bears still the name 
of the latter. Afterward the country passed into the hands 
of Spaniards, and during that period, in 1763, a valuable 
mine was opened by Francis Burton, since called Mine a 
Burton. | 

The lead region of Wisconsin, according to Dr. D. D. 
Owen, comprises 62 townships in Wisconsin, 8 in Iowa, and 
10 in Illinois, being 87 miles from east to west, and 54 
miles from north to south. The ore, as in Missouri, is 
abundant. The ore, according to Whitney, occupies cavi- 
ties or chambers in the limestone instead of true veins, and 
in this respect it is like that of Derbyshire and Northern 
England. 

The mines of Wisconsin and Illinois are in Lower Silurian 
limestone of the Trenton period, called the Galena lime- 
stone ; those of Southeastern Missouri, situated chiefly in 
Franklin, Jefferson, Washington, St. Frangois, St. Gene- 
vieve, and Madison counties, are in the *‘ Third Magnesian 
limestone ;” also Lower Silurian, but of the Calciferous or 
Potsdam period ; those of Southwestern Missouri, situated 
mostly in Newtown, Jasper, Lawrence, Green, and Dade 
counties, and in the western part of McDonald, Barry, 
Stone, and Christian counties, are in the ‘‘ Keokuk lime- 
stone,” of the Subcarboniferous period, but partly in Web- 
ster, Taney, Christian, and Barry counties, in the Lower 
Silurian ‘‘ magnesian limestone ;” those of Central Mis- 
souri, situated in Moniteau, Cole, Miller, Morgan, and 
other counties, are mostly in the Lower Silurian ‘‘ magne- 
sian limestone,” but partly, as in Northern Moniteau, in 
the Subcarboniferous. ‘The conditions in which the ore 
occurs in Missouri confirms the opinion of Prof. Whitney, 
as to there being no true veins. Mr. Adolph Schmidt, in 
his account of the Missouri lead ores, says that the deposits 


LEAD. 163 


contain red clay, broken chert, from the chert bed, and 
portions of the limestone beds, along with the lead ; that 
the barite was introduced after the lead ; that some caves 
are filled through all their ramifications, while others are 
only partly filled; and he adds that the same solvent waters 
that made the caves and horizontal fissures or openings 
may have held the various minerals in solution. In Derby- 
shire, England, the deposits contain fossils of Permian 
rocks, showing that, although occurring in Subcarbonif- 
erous limestone, they were much later in origin. 

In Colorado, at Leadville, there are very productive 
mines, which yield also gold and silver; also at the mines of 
Georgetown, in Clear Creek Co., and in the San Juan 
district ; in Montana at several localities; in Idaho; in 
Arizona; in Nevada abundant in the Eureka district, the 
principal mines of which are the Richmond and Eureka; 
also in the Castle Dome and other districts; in Utah at 
several mines ; in California, in Inyo Co.; in New Mexico, 
in the Magdalena Mountains, Socorro Co.; and in Los 
Cerillos district, Santa Fé Co. 

Galenite also occurs much less abundantly in the region 
of Chocolate River and elsewhere, Lake Superior copper 
region ; on Thunder Bay and Black Bay ; at Cave-in-Rock, 
Ill., along with fluorite; at Rossie, in St. Lawrence Co., 
N. Y., in gneiss, in a vein 3 to 4 feet wide near Wurtz- 
boro’ in Sullivan Co., a large vein in millstone grit, at 
Ancram, in Columbia Co., Martinsburg, in Lewis Co., and 
Lowville; at Lubec ; and of less interest at Blue Hill Bay, 
Birmingham and Parsonsfield, Me.; at Eaton, Bath, Tam- 
worth, and Haverhill, N. H.; at Thetford, Vt.; at South- 
ampton, Leverett, and Sterling, and Newburyport, Mass. ; 
at Middletown, Ct., formerly worked as a silver-lead mine; 
in Wythe County, Louisa County, Va., and elsewhere ; 
at King’s Mine, Davidson Co., N. C., where the lead ap- 
pears to be abundant; at Brown’s Creek, and at Haysboro’, 
near Nashville, Tenn.; at Pheenixville, Pa.; in Michipi- 
coten and Spar Islands, Lake Superior. 

The lead of commerce is obtained from this ore. It is 
also employed in glazing common stoneware: for this pur- 
pose it is ground to an impalpable powder and mixed in 
water with clay; into this liquid the earthen vessel is dipped 
and then baked. 


164 DESCRIPTIONS OF MINERALS. 


Retzbanyite, Cosalite. Lead sulpho-bismuthide; steel-gray. Cosala 
and Sinalva, Mexico; Retzbanya, Hungary. 

Begeerite, ‘another sulpho- bismuthide. Baltic Lode, Col. 

Bjelkite. Near Cosalite. Bjelka mine, Sweden. 


LEAD SELENIDES AND TELLURIDES. 


These various ores of lead are distinguished by the fumes B.B., and 
by yielding, on charcoal, ultimately, a globule of lead. 

Clausthalite, Lead selenide , lead- -gray; fracture granular, occasion- 
ally. foliated; H. = 2:5-8; G. = 7°6-8°8; B.B. on charcoal a horse- 
radish odor (that of selenium). The Hartz. <A lead and copper scle- 
nide (Zorgite) has G. = 7-7°5. A lead and mercury selenide (Lehr- 
bachite) occurs in foliated grains or masses of a lead-gray to bluish 
and iron-black color. 

Altaite, or Lead telluride. Tin white; cleavable; H. = 3-3°5; G. = 
8-16. The Altai. 

Nagyagite, Foliated tellurium. Remarkable for being foliated like 
graphite; co:or and streak blackish lead-gray; H. =1-1°5; G.= 
7085; contains Tellurium 32°2, lead 54:0, gold 9°0, with often vt 
copper, and some sulphur. Transylvania. 


SULPHARSENITES, SULPHANTIMONITES, AND SULPHO-BISMUTHITES. 


These species include, of (A) SULPHARSENITES: Freteslebenite (p 
183), Sartorite, Dufrenoysite, Guitermanite ; of (B) SULPHANTIMO- 
NITES: Tamesonite, Boulangerite, Zinkenite, Plagionite, Semseyite, 
Brongniardite (p. 138), Meneghinite, Geocronite, Diirfeidtite, Plumbo- 
stannite (containing 16 p. c. tin); of (C) SULPHO- BISMUTHITES: SJobel- 
lite, Aikinite, Alaskaite, Galenobismutite. Of these only Jamesonite, 
Boulangerite, Zinkenite, Aikinite, Kobellite occur often in fibrous 
forms. 

A. Dufrenoysite. Orthorhombic; blackish lead-gray. Binnen. 

Jamesonite. Orthorhombic; usually fibrous (Feather ore), also mas- 
sive; lead-gray; G. = 5'd-5° 7. Cornw all; Hungary; Siberia; Tus- 
cany; Arkansas. 

Guitermanite. Bluisb gray, slightly metallic; G. = 5°94; about 62 
p. c. of lead. The Zufii mine, San Juan Co., Col. 

B. Boulangerite. Plumose and massive; bluish lead-gray; G. = 
5'75-6. Moliéres, France; Wolfsberg, Hartz; Tuscany. 

Zinkenite. Orthorhombiec: color and str eak steel-gray; G. = 5°30- 
to 5°35. Wolfsberg, Hartz; Brobdignag mine, San Juan Co., Col. 

Plagionite. Monoclinic ; blackish lead-gray; G. =5°4. Wolfs- 
berg. 

Meneghinite. Monoclinic; G. = 6°4. Bottino, Tuscany; Marble 
Lake, Ontario, Canada. 

Aitkinite (Needle ore). Acicular crystals and massive; contains cop- 
per with the lead. Beresof, Ural; gold region, Geor cia. 

C. Kobellite. Resembles stibnite. Contains 40 p. c. of Jead and 
27 of bismuth. Sweden; near Leadville, on Printerboy Hill, Col. 
(affording about 44 p. c. of lead and 33 of bismuth). 

Galenobismutite. Contains 27 p. c. of lead to 54 of bismuth. 
Sweden. 


LEAD. 165 


Alaskaite. Massive, whitish lead-gray. Contains lead and silver, 
with 45 to 57 p.c. of bismuth. Alaska mine, San Miguel Co. (San 
Juan region), Col. 


OXIDES. 
Minium.—Oxide of Lead. 


Pulverulent. Color bright red, mixed with yellow. G. = 
46. Composition, Pb,O,  B.B. affords globules of lead in 
the reduction flame. 

Obs. Occurs at various mines, usually associated with 
galena, and is found at Austin’s Mines, Wythe Co., Va.; 
with cerussite. 

Uses. Minium is the red lead of commerce; but for the 
arts it is artificially prepared. 


Plumbie ochre. ead protoxide; color yellow. 

Mendipite. Oxthorhombic; white, yellowish or reddish; nearly 
op.que; pearly; G. = 7-7'1; PbCi, + PbO = Chloride of lead 88°4, 
lead oxide 61°6. Mendip Hills. Jfatlockite is PbzOCl.. 

Ootunnite. Chloride of lead, PbCl.; acicular crystals; white ; 
contains 74°5 per cent. of lead. Vesusius. 

Plumbogummite. In globular forms ; yellowish or reddish-brown ; 
lustre somewhat like gum arabic; H. =4-45; G. =6°3-6°4; also 
a variety 4-4°9 ; consists of lead, alumina, and water. Huelgoet in 
Brittany ; lead-mine in Beaujeu; the Missouri mines, with black 
cobalt ; Canton mine, Ga. 


SULPHATE, CHROMATES, TUNGSTATE, MOLYBDATE, 
Anglesite.—Lead Sulphate. 


Orthorhombic; JA J = 103° 483’. 
In rhombic prisms and other forms. 
Lateral cleavage. Also massive ; 
lamellar or granular. 

Color white or slighly gray or 
green. Lustre adamantine ; some- 
times a little resinous or vitreous. 
Transparent to nearly opaque. Brit- 
tle. H.=2°75-3. G. = 6°35-6°4. 

Composition. PbO,S (or PbO + 
SO,), affording about 73 per cent. 
of lead oxide. B.B. fuses in the flame of a candle; on 
charcoal, with soda, yields lead. 

Diff. Distinguished by its specific gravity, and by yield- 
ing lead. B.B differs from lead carbonate in lustre, and 
in not dissolving with effervescence in acid. 





166 DESCRIPTIONS OF MINERALS. 


Obs. Usually associated with galenite, and results from 
its decomposition. Occurs in fine crystals at Leadhills and 
Wanlockhead, Great Britain, and also at other foreign lead- 
mines. Inthe United States, at the lead-mines of Missouri 
and Wisconsin; in fine crystallizations at Phoenixville, 
Pa.; sparingly at the Walton gold-mine, Louisa Co., Va.; 
at Southampton, Mass.; in Arizona, in many mines; Cerro 
ke Cal.; Clear Creek and Lake Cos., Col.; Nevada; 

tah. 


Linarite. WHydrous lead-copper sulphate; deep azure-blue; one 
perfect cleavage; G. = 5°8-5°45. Leadhills, Red Gill, Keswick ; 
Schneeberg ; Urals. 

Lead Sulphato-carbonates, Anhydrous.—Caledonite. Color verdi- 
gris to bluish green. Leadhills, ete.; Mine la Motte, Mo. 

Leadhillite (Mazite). Orthorhombic; white, yellow, gray; G.= 
6°25-6°45. Leadhills, etc. Susannite; the same, but rhombohedral. 

Lanarkite. Monoclinic ; white, yellowish, gray, greenish; G. = 
6°3-7. Leadhills, Lanarkshire, Scotland ; Siberia ; Hartz; Tyrol. 


Crocoite.—Crocoisite. Lead Chromate. 


Monoclinic. In oblique rhombic prisms, massive, of a 
bright red color and translucent. Streak orange-yellow. 
H. =2°5-3. G. =5°9-6°1. 

Composition. PbO,Cr (or PbO-+ CrO,) = Chromium 
trioxide 31:1, lead oxide 68°9. Blackens and fuses, and 
forms a shining slag containing globules of lead, 

Obs. Occurs in gneiss at Beresof in Siberia, and also in 
Brazil; Vulture region, Arizona. ‘This is the chrome 
yellow of the painters. 


Phenicochroite (or Melanochroite). Another lead chromate; con- 
tains 23°0 of chromium trioxide, and is dark red ; streak brick-red ; 
crystals usually tabular and reticulately arranged; G. = 5°75. 
Siberia; Arizona. 

Vauquelinite. A lJead-copper chromate; very dark green or pearly 
black ; usual in minute irregularly aggregated crystals; also reni- 
form and massive; H. = 2°5-8; G. =5°'5-5'8. Siberia; Brazil; 
lead-mine near Sing Sing, mammillary ; Arizona. 

Stolzite, or Lead tungstate. In square octahedrons or prisms ; green, 
gray, brown, or red. Lustre resinous; H. = 2°5-3; G. = 79-81; 
contains 51 of tungstic acid and 49 of lead. Zinnwald. 

Wulfenite, or Lead molybdate. In tetragonal crystals, octahedral 
and tabular; also massive; yellow; lustre resinous; contains 
molybdenum trioxide 34°25, lead protoxide 64°42. Bleiberg and else- 
where in Carinthia ; Hungary ; sparingly at Southampton, Mass.; in 
fine crystals at Phoenixville, Pa.; at Tecoma and Eureka, Nev.; 
Silver and other districts, Arizona ; in Los Cerillos, N. Mexico. 


LEAD. 169% 


PHOSPHATES, ARSENATES, VANADATES, ANTIMONATES. 
Pyromorphite.—Lead Phosphate. 


Hexagonal. In hexagonal prisms; often 
in crusts made of crystals. Also in globules 
or reniform, with a radiated structure. 

Color bright green to brown ; sometimes 
fine orange-yellow, owing to an intermixture 
with chromate of lead. Streak white or 
nearly so. Lustre more or less resinous. 
Nearly transparent to subtranslucent. Brit- 
tle. i. = 3°5-4. G. = 6°8-7:1; impure 5-6, 

Composition. Pb,O,P,-+4PbCl, (or 3 PbO + P.O, +4 
PbCl,) = Phosphorus pentoxide 15°71, lead oxide 82°2%, 
chlorine 2°62 = 100°60. B.B. fuses easily in the forceps, 
coloring the flame bluish green. On charcoal fuses, and 
on cooling the globule becomes angular; coats the coal 
white from the chloride, and, nearer the assay, yellow from 
lead oxide. Soluble in nitric acid. 

Diff. Has some resemblance to beryl and apatite, but is 
quite different in its action before the blowpipe, and much 
higher in specific gravity. 

Obs. Leadhills, Wanlockhead, and some lead-mines of 
Europe are foreign localities. In the U. States, well crys- 
tallized at King’s Mine, in Davidson Co., N. C.; other 
localities are the Perkiomen and Phoenixville mines, Pa.; 
Lubec lead-mines, Me.; Lenox, N. Y.; formerly, a mile 
south of Sing Sing, N. Y.; the Southampton lead-mine, 
Mass.; sparingly in Arizona, Mexico, New Mexico, and 
Nevada, where the phosphate is replaced by vanadate. 

The name pyromorphite is from the Greek pur, fire, and 
morphe, form, alluding to its crystallizing on cooling from 
fusion before the blowpipe. 





Mimetite. A lead arsenate, resembling pyromorphite in crystalliza- 
tion, but giving a garlic odor on charcoal B.B.; pale yellow, passing 
into brown; H. = 2°75-3°5; G. = 6°41; composition, Pb;O;As.-+ 4 Pb 
Cl, = Arsenic pentoxide 23°20, lead oxide 74°96, chlorine 2°30 = 100-55, 
Cornwall and elsewhere; Phoenixville, Pa.; Vulture distr., Arizona. 
findlichite is a vanadiferous mimetite from New Mexico. 

Hedyphane is a variety of mimetite containing much lime; amor. 
phous; whitish; lustre adamantine; H. = 35-4; G. = 5°4-5°5. Long. 
ban, Sweden. 

Karyinite. A lead arsenate containing manganese and calcium, 
Norway. 

Ficdemiie. Lead chloro-arsenate; yellow to green. Sweden. 


168 DESCRIPTIONS OF MINERALS. 


Achrematite. Lead arsenate and molybdate; color yellow to red. A 
doubtful species. Mexico. 

Phosphochromite. A chromate and phosphate. Beresof. 

Vanadinite. A lead vanadate. Hexagonal; in prisms like pyro- 
morphite, and also in implanted globules; yellow to reddish brown and 
red; H. = 2°75-3; G. = 69-7°23. Zimapan, Mexico; in the silver dis- 
tricts of Arizona in red and orange crystals; Los Cerillos, N. Mexico. 
Wanlockhead in Dumfriesshire. 

Descloizite. Lead vanadate; orthorhombic; black, brown, olive- 
green. Cordoba; New Mexico; Arizona; Carinthia. 

Brackebuschite. A hydrous lead vanadate. Cordoba. 

Dechenite. A ead-silver vanadate. Dahn and Freiberg. 

Mottrammite. Lead-copper vanadate; black. Mottram, St. An- 
drews, England. 
Se ge Lead-copper vanadate; olive-green, blackish. Laurium, 

reece. 

Psittacinite. Lead-copper vanadate; green to olive-green. Mon- 
tana. 

Tritochorite. Lead-copper-zine vanadate; S. America or Mexico. 

Monimolite. A yellow lead antimonate. 

Nadorite. A yellow lead chlor-antimonate. 

Arequipite. Lead silico-antimonate; wax-like yellow. Peru. 

Coronguite. A doubtful lead-silver antimonate. 

Bindheimite. A hydrous lead antimonate. 
_ Molybddomenite. Lead selenite. Cacheuta, S. A. 


CARBONATES, SILICATES. 
Cerussite.— White Lead Ore. Lead Carbonate. 


Orthorhombic; 7A J=117° 13’. In modified right rhom- 
bic prisms; often in compound crystals, two or three cross- 





ing one another as in Fig. 2. Also in six-sided prisms 
like aragonite. Also massive; rarely fibrous. 

Color white, grayish, light or dark. Lustre adamantine. 
Brittle. H.=3-3°5. G. = 6:46-6:48. 

Composition. PbO,C (or PbO + CO,) = Carbon dioxide 
16°5, lead oxide 83°5 = 100. B.B. decrepitates, fuses, and 
with care on charcoal affords a globule of lead. Effervesces 
in dilute nitric acid. 


LEAD. 169 


Diff. Distinguished by its specific gravity and yielding 
lead when heated. From anglesite it differs in giving lead 
alone on charcoal B.B., as well as by its solution and effer- 
vescence with nitric acid, and its less glassy lustre. 

Obs. Associated usually with galena. Finely crystallized 
at Leadhills, Wanlockhead, and Cornwall; also Linares, 
Spain, and other lead-mines in Europe. 

In the U.S., at Austin’s Mines, Wythe Co., Va.; at 
King’s Mine, in Davidson Co., N. C.; at the latter 
place it has been worked for lead, and it is associated 
with native silver and pyromorphite; Perkiomen and 
Pheenixville, Pa.; at ‘‘Vallée’s Diggings,” Jefferson Co., 
Mo., and other mines in that State; at Brigham’s Mine, 
near the Blue Mounds, Wis., partly in stalactites; at ‘‘ Deep 
Diggings,” in crystals, and at other places, both massive 
and in fine crystallizations; in Colorado and many Western 
mining regions with other lead ores, 

When abundant, this ore is wrought for lead. Large 
quantities occur about the mines of the Mississippi Valley. 
It was formerly buried up in the rubbish as useless, but it 
has since been collected and smelted. It is a rich ore, af- 
fording in the pure state 75 per cent, of lead. 

The ‘‘ white lead” of commerce, extensively used as a 
paint; but the material so used is artificially made. 


Phosgenite, or Corneous Lead. A lead chloro-carbonate, occurring 
in whitish adamantine crystals. H. = 2°75-4, G. = 6-6°3. Composi- 
tion, PbO;C+-PbCl:. Derbyshire and Germany. 

Hydrocerussite. Hydrous lead carbonate, on native lead. From 
Sweden. 

Ganomalite. A white lead-manganese silicate, affording 34°89 per 
cent. of lead oxide. Sweden. Hyalotecite is a lead-barium-lime sili- 
cate. Melanotecite is a lead-iron silicate. Kentrolite isa lead-manga- 
nese silicate; G. = 6°19. 


General Remarks.—The lead of commerce is derived almost wholly 
from the sulphide of lead or galenite, the localities of which have 
already been mentioned; yet in some mining regions, the carbonate and 
sulphate are also abundant. 

The lead-mines of the Central United States afforded in 1826, 1770 
tons; in 1842, 24,000 short tons; in 1872, 25,880; 1875, 60,000; 1877, 
82,000; 1880, 98,000; 1884, 140,000 short tons. 

In 1884, Nevada produced 4000 tons; Utah, 28,000; Colorado, 63,165; 
Montana,7000; Idaho, 7500; N. Mexico, 6000; Arizona, 2700; California, 
1000; the States on the Mississippi, 19,676; Virginia, 256. Great Britain 
produced in 1874 about 59,000 long tons; in 1888, 39,160. In 1888, 
Germany produced 96,400 tons; Spain, 129,000 tons; France, 8000 
tons; Italy, 9000 tons; Austria, 11,320 tons. 


170 DESCRIPTIONS OF MINERALS. 


ZINC. 


Zine occurs in combination with sulphur and oxygen; 
and also in the condition of silicate, carbonate, sulphate, 
and arsenate. It is also a constituent of one variety of the 
species spinel. The chief sources of the metal are smith- 
sonite or the carbonate; willemite and calamine, or silicates; 
zincite, or the oxide; sphalerite (blende), or the sulphide; 
and franklinite. Native zinc has been reported from 
Northern Alabama. 


Sphalerite—Blende. Zinc Sulphide. Black Jack. 


Tsometric. In dodecahedrons, octahedrons, and othor 
allied forms, with a perfect dodecahedral cleavage. Also 
massive; sometimes fibrous. Color wax-yellow, brownish 
yellow to black, sometimes green, red, and white; streak 


1. 2. 3. 





white to reddish Drown. Lustre resinous or waxy, and 
brilliant on a cleavage face; sometimes submetallic. ‘Trans- 
parent to subtranslucent. Brittle. H.=3-5-4. G.=3:9-4:°2. 
Some specimens become electric with friction, and give off 
a yellow light when rubbed with a feather. 

Composition. ZnS =Sulphur 33, zinc 67=100. Con- 
tains frequently iron sulphide when dark-colored; often 
also 1 or 2 per cent. of cadmium sulphide, especially the 
red variety; also sometimes indium and gallium. Nearly 
infusible alone and with borax. Dissolves in nitric acid, 
emitting sulphuretted hydrogen. Strongly heated on char- 
coal yields fumes of zinc. 

Diff. This ore is characterized by its lustre, cleavage, 
and its being nearly infusible. Some dark varieties took a 
little like tin ore, but their cleavage and inferior hardness 
distinguish them; and some clear red crystals, which resem- 


ZINC. 17] 


ble garnet, are distinguished by the same characters and 
also by their very difficult fusibility. 

Obs. Occurs in rocks of all ages, associated generally 
with ores of lead, and often also with copper, iron, tin, and 
silver ores. ‘The lead-mines of Missouri and Wisconsin 
afford this ore abundantly. Other localities are, at Lubec, 
Bingham, Dexter, Parsonsfield, Me.; at EHaton, Warren, 
Haverhill, Shelburne, N. H.; at Hatfield, Vt.; in Brook- 
field, Berlin, Roxbury, and Monroe, Ct.; at Ancram lead- 
mine, the Wurtzboro’ lead vein, at Lockport, Root, 2 miles 
southeast of Spraker’s Basin, in Fowler, at Clinton, N. Y.; 
at Franklin, N. J., colorless (Cletophane); at the Perkio- 
men lead mine, Pa.; and a compact variety abundant at 
Friedensville, Saucon Valley, Pa.; with calamine in lower 
Silurian limestone, at Austin’s lead mine, Wythe Co., Va.; 
near Powell’s River, and at Haysboro’, Tenn.; at Prince’s 
Mine, Spar Island, Lake Superior, with ores of silver; in 
Beauce Co., Canada, where it is slightly auriferous; also at 
various mines in Colorado, Arizona, Utah, Montana, New 
Mexico, Idaho, California; in fine crystals at Joplin, Mo. 

A useful ore of zinc, though more difficult of reduction 
than calamine. By its decomposition (like that of pyrite) 
it affords sulphate of zinc or white vitriol. 


- Wurtzite. Zinc sulphide in hexagonal crystals. From Bolivia; 
Butte Mine, Montana. Hrythrozincite is supposed to be a manganesian 
variety of wurizite. 

Huascolite is a zinc-lead sulphide. Yowngite is probably a mixture. 


Zincite.-—Red Zinc Ore. Zinc Oxide. 


Hexagonal. Usually in foliated masses, or in dissemi- 
nated grains; cleavage eminent, nearly like that of mica; 
but the lamin brittle, and not so easily separable. 

Color deep or bright red, by transmitted light deep 
yellow; streak orange-yellow. Lustre brilliant, subadaman- 
tine. ‘Translucent or subtranslucent. H. =44°5. G.= 
5°68-5°74. 3 

Composition. ZnO = Oxygen 19°7, zine 80°3 = 100. 
B.B. infusible alone, but yields a yellow transparent glass 
with borax; on charcoal, a coating of zinc oxide. Dissolves 
in nitric acid without effervescence. 

Diff. Distinguished by its eminent cleavage, infusibility, 
and also by its mineral associations. 


172 DESCRIPTIONS OF MINERALS. 


Obs. Occurs with franklinite at Mine Hill and Sterling 
Hill, Sussex Co., N. J. 
A good ore of zinc, and easily reduced. 


Voltzite. Sulphur, oxygen and zinc, 4ZnS-+ ZnO; in implanted 
globules; dirty rose-red; pearly on a cleavage surface. France; near 
Joachimstahl. 

Hydrofranklinite. Isometric octahedrons; iron black; supposed to 
be hydrous oxide of zinc and iron. Sterling Hill, N. J. 


Goslarite.—Zinc Sulphate. White Vitriol. 


Orthohombic; JA J = 90° 42’. Cleavage perfect in one 
direction. 

Color white. Lustre vitreous. Easily soluble; taste as- 
tringent, metallic, and nauseous. Brittle. H. = 2-275. 
G. = 2°086; artificial, 1:95-1:96. 

Composition. ZnO,8S + 7 aq. (or ZnO + SO, + 7 aq.) = 
Zinc oxide 28°2, sulphur trioxide 27°9, water 43°9 = 100. 
B.B. gives off fumes of zine on charcoal, which cover the 
coal. 

Obs. Results from the decomposition of blende. Occurs 
in the Hartz; Hungary; Sweden; at Holywell in Wales. 

Hxtensively employed in medicine and dyeing. Prepared 
to a large extent from blende by decomposition, though 
this affords, owing to its impurities, an impure sulphate. 
Also obtained by direct combination of zinc with sulphuric 
acid. 

White Vitriol, as the term is used in the arts, is one form 
of sulphate of zinc, made by melting the crystallized sul- 
phate, and agitating till it cools and presents an appearance 
like loaf sugar. 


Zinc-aluminite. Hydrous zinc-aluminum sulphate; white. Lau- 
rium, Greece. 

Hopeite. In orthorhombic crystals; grayish white; supposed to be 
a hydrous zinc-phosphate. Altenberg zinc mines. 

Kottigite. Hydrous zinc-cobalt arsenate; reddish (owing to pres- 
ence of cobalt). Schneeberg. 

Adamite. Uydrous zinc-arsenate; honey-yellow to violet. Chili. 


Smithsonite.—Zine Carbonate, 


Rhombohedral; 2A R=107° 40’. Cleavage FR perfect. 
Massive or incrusting; reniform and stalactitic. 
Color impure white, sometimes green or brown; streak 


ZINC. We) 


uncolored. Lustre vitreous or pearly. Subtransparent to 
translucent. Brittle. H.=5. G. = 4:3-4°45, 

Composition. ZnO,C (or ZnO + CO,) = Carbon dioxide 
35°2, zinc oxide 64°8 fouwr-fifihs of which is pure zinc) = 
100. Often contains somecadmium. B.B. infusible alone, 
but carbonic acid and oxide of zinc are finally vaporized. 
liffervesces in nitric acid. Negatively electric by friction. 

Diff. The effervescence with acids distinguishes this 
mineral from the following species; and the hardness, diffi- 
cult fusibility, and the zinc fumes before the blowpipe, from 
the carbonate of lead or other carbonates. Besides, the 
crystals over a drusy surface terminate usually in sharp 
three-sided pyramids. 

Obs. Occurs commonly with galena or blende, and 
usually in calcareous rocks. Found in Siberia, Hungary, 
Silesia; at Bleiberg in Carinthia; near Aix-la-Chapelle in 
the Lower Rhine, and largely in Derbyshire and elsewhere 
in England. In the U. States, abundant at Joplin 
Creek, Mine-la-Motte, Mo., and Vallée’s Diggings; at lead 
“‘digoings” in Iowa and Wisconsin; in Hastern Kansas, 
near the Joplin Mines; also in Claiborne Co., Tenn.; 
sparingly at Hamburg, near Franklin Furnace, Sussex Co., 
N. J.; Perkiomen lead mine, Pa. 

Hydrozincite (Zine Bloom). Hydrous zine carbonate, ZnO;C 4- 
2Zn02H, of a whitish color, with G. = 3°58-3°8 

Aurichaleite. ydrous zinc-copper carbonate; in drusy incrusta- 
tions of acicular crystals; pale verdigris-green to sky-blue. Siberia, 
Hungary, England, France, Tyrol, Spain; Lancaster, Pa. 

Buratite. A lime aurichalcite. 


Willemite.—Zinc Silicate. Troostite. 


Rhombohedral; RA #=116° 1’. In hexagonal prisms; 
also massive. 

Color whitish, greenish yellow, apple-green, flesh-red, 
yellowish brown. Streak uncolored. ‘Transparent to 
opaque. Brittle. H.=5°5. G. = 3°89-4°18. 

Composition. Zn,O,Si(or2Zn0+Si0,)= Silica 27:1, zine 
oxide 72°9= 100. B.B. fuses with difficulty to a white 
enamel; on charcoal, and most easily on adding soda, yields 
a coating which is yellow while hot, and white on cooling, 
and which, moistened with cobalt solution and treated in 
O.F., is colored bright green. Gelatinizes with hydro- 
chloric acid. 


174 DESCRIPTIONS OF MINERALS. 


Obs. From Moresnet, between Liége and Aix-la-Cha. 
pelle; Raibel in Carinthia; Greenland. Abundant at 
Franklin and Sterling, Sussex Co., N. J., mixed with 
zincite, and used as an ore of zinc; also in prismatic 
crystals that occasionally are six inches long. 


Calamine.—Hydrous Zinc Silicate. Galmei. 


Orthorhombic; 7A 7=104° 13’. In rhombic prisms, 
the opposite extremities with unlike planes. Cleavage per- 
fect parallel to 7. Also massive and incrusting, mammil- 
lated or stalactitic. 

Color whitish or white, sometimes bluish, greenish, or 
brownish. Streak uncolored. ‘Transparent to translucent. 
Lustre vitreous or subpearly. Brittle. H. =4:5-5. G= 
3°16-3°9; 3°45-3°49. Altenberg. Pyro-electric. 

Composition. H,Zn,O,Si = Silica 25:0, zinc oxide 67°5, 
water 7°5 = 100. 

B.B. alone almost infusible. Forms a clear glass with 
borax. Dissolves in heated sulphuric acid; the solution 
gelatinizes on cooling. 

Diff. Differs from calcite and aragonite by its action 
with acids; from a salt of lead, or any zeolite, by its infusi- 
bility; from chalcedony by its inferior hardness, and its 
gelatinizing with heated sulphuric acid; from smithsonite 
by not effervescing with acids, and by the rectangular 
aspect of its crystals over a drusy surface. 

Obs. Occurs with galenite. In the United States it is 
found at Joplin Creek, Granby Dist., Mine La Motte, and 
Vallée’s Diggings, Mo.; Perkiomen and Phoenixville lead 
mines; at F’riedensville in Saucon Valley, two miles from 
Bethlehem, Pa.; abundantly at Austin’s Mines, Wythe 
Co., Va. Valuable as an ore of zinc. 


Franklinite, an ore of iron, containing manganese and zinc; see 
page 


General Remarks.—The metal zinc (spelter of commerce) is supposed 
to have been unknown in the metallic state to the Greeks and Romans. 
It has long been worked in China, and was formerly imported in 
large quantities by the East India Company. 

The principal mining regions of zinc in the world are in Upper 
Silesia, at Tarnowitz and elsewhere; in Poland; in Carinthia, at 
Raibel and Bleiberg ; in Netherlands at Limberg ; at Altenberg, near 
Aix-la-Chapelle in the Prussian province of the Lower Rhine; at 
Vieille Montagne in the Liége district, Belgium; in England, in 
Derbyshire, Alstonmoor, Mendip Hills, etc.; in the Altai, in Russia; 


CADMIUM. 175 


besides others in Italy, Greece, Sweden, and China. In the U. States, 
smithsonite and calamine occur with the lead ore of Missouri in large 
quantities. They were formerly considered worthless and thrown 
aside, under the name ot ‘‘dry bone.” In Tennessee, Claiborne Co., 
there are workable mines. Calamine occurs at Friedensville, Pa., 
along with massive blende: it is not now worked. The zincite, wille- 
mite, and franklinite of Franklin, N. J., are together worked as a 
zinc ore, and both zinc and zinc oxide are produced. Blende is 
sufficiently abundant to be worked at the Wurtzboro’ lead mine, 
Sullivan Co., New York , at Eaton and Warren, in N. H; at Lubec, 
Me. ; at Austin’s Mine, Wythe Co., Va.; at some of the Missouri lead 
mines. 

The amount of zinc produced in 1885, in Europe, was, for Belgium 
and the Rhine, 129,784 long tons; Silesia, 79,623; Poland, 5,000; 
Austria, 2,928; France and Spain, 15,000; Great Britain, 23,100; 
United States, 34,000 ; making in all about 290,000 long tons. In 
1884 Illinois produced about 16,000 tons; Kansas, over 7000; Mis- 
souri, nearly 5000; and the Eastern and Southern States, 7050. Market 
price per pound, 4 to 4°65 cents. 

Zinc is a brittle metal, but admits of being rolled into sheets when | 
heated to about 212° F. In sheets it is extensively used for roofing 
and other purposes, it being of more difficult corrosion, much harder, 
and also very much lighter than lead. It is also employed largely for 
- coating (that is, making what is called galvanized) iron. Its alloys 
with copper (page 159) are of great importance. 

The white oxide of zinc is much used for white paint, in place of 
white lead; and also in making a glass for optical purposes. 

An impure oxide of zinc, called cadmia, often collects in large quan- 
tities in the flues of iron and other furnaces, derived from ores of zine 
mixed with the ores undergoing reduction. A mass weighing 600 
pounds was taken from a furnace at Bennington, Vt. It has been ob- 
served in the Salisbury iron furnace, and at Ancram, in New Jersey, 
where it was formerly called Ancramvite. 


CADMIUM. 


Only two ores of this metal are known; but it exists 
with zinc in sphalerite, smithsonite and calamine. The 
cadmiferous sphalerite is called Przibramite. The metal 
cadmium (discovered by Stromeyer in 1818) is white like 
tin, and is so soft that it leaves a trace upon paper. It 
fuses at 442° F. 


Greenockite, In hexagonal prisms; light-yellow; lustrous and nearly 
transparent; H. = 3-3°5; G. = 4°8-5. Bishopton, Scotland; Bohemia, 
on blende; Friedensville, Lehigh Co., Pa. 

Hogenite. In translucent orthorhombic crystals; light grayish-brown; 
lustre subadamantine; H. = 4-5; B.B. infusible; supposed to be a 
silicate of cadmium. On calamine at Altenberg. 


176 DESCRIPTIONS OF MINERALS. 


TIN. 


Tin has been reported as occurring native in the gold 
washings of the Ural, and in Bolivia. There are two ores, 
a sulphide and an oxide. It is also contained in some ores 
of niobium, tantalum, and tungsten. 


Stannite.—Tin Pyrites. Sulphuret of Tin. Tin Sulphide. 


Commonly massive, or in grains. Color steel-gray to 
iron-black; streak blackish. Brittle. H.=4. G@. =43- 
4:6. 

Composition. Sulphur 30, tin 27, copper 30, iron 13 = 100. 

Obs. From Cornwall, where it is often called dell-metal 
ore, from its frequent bronze-like appearance; also from 
Ireland and the Erzgebirge. 


Cassiterite.—Tin Ore. Tin Oxide. 


Tetragonal. In square prisms and octahedrons; often in 
twins; 1 A 1 = 121° 40's 
ib 1i A li (over the summit) 2. 
112° 10’ (over a ter- 
minal edge) 133° 31’. 
Cleavage indistinct. Also 
massive, and in grains. 

Color brown, black 
yellow; lustre of crystals 
high adamantine. Streak 
pale gray to brownish. 
Nearly transparent to 
opaque. H.=6-%. G. of light-colored, 6°4-6°85; of dark, 
6°8-7°02. 

Composition. SnO,= Oxygen 21°33, tin 78°67; often 
contains a little iron, and sometimes tantalum. B.B. alone 
infusible. On charcoal with soda, a globule of tin. 

Stream tin is the gravel-like ore found in débris in low 
grounds. Wood tin occurs in botryoidal and reniform shapes 
with a concentric and radiated structure ; and toad’s-eye tin 
is the same on a small scale. 

Diff. Has some resemblance to a dark garnet, to black 
zinc blende, and to some varieties of tourmaline. Distin- 
guished by its infusibility, and its yielding tin before the 





TIN. UG 


blowpipe on charcoal with soda. Differs from blende also 
in its superior hardness. 

Obs. 'Tin ore occurs in veins in granite, a quartzose 
gneiss, and mica schist, associated often with wolfram, 
pyrite, topaz, tourmaline, mica or talc, and albite. Corn- 
wall is one of its most productive localities; also worked in 
Saxony, at Altenberg, Geyer, Ehrenfriedersdorf and Zinn- 
wald; in Austria. at Schlackenwald and other places; in 
Malacca, Pegu, China, and especially the Island of Banca 
in the Hast Indies; in Queensland and Northern New South 
Wales, Australia, in large quantities; in Greenland. Oc- 
curs also in Galicia, Spain; at Dalecarlia in Sweden; in 
Russia; in Mexico at Durango; and Bolivia. In the 
United States found sparingly at Chesterfield and Goshen, 
Mass.; at Winslow, Me.; Lyme and Jackson, N. H.; in the 
eastern corner of Rockbridge Co., Va.; Ashland, Clay Co., 
Ala.; valuable veins in the Black Hills, Dakota, in the 
Harney range; in the Temescal Range, and at San Diego, 
Cal.; on Jordan R., Idaho; in Montana, near Helena; Nig- 
ger Hill, Wyoming. 


General Remarks.—The principal tin mines now worked are those 
of Cornwall; Banca, Malacca, and Australia. 

The Cornwall mines were worked long before the Christian era. 
Herodotus, 450 years before Christ, is believed to allude to the tin 
islands of Britain under the cabalistic name Cassiterides, derived from 
the Greek kasstteros, signifying tin. 'The Pheenicians are allowed to 
have traded with Cornubia (as Cornwall was called, it is supposed 
from the horn-like shape of this extremity of England). The Greeks 
residing at Marscilles were the next to visit Cornwall or the isles ad- 
jacent, to purchase tin; and after them came the Romans, whose 
merchants were long foiled in their attempts to discover the tin market 
of their predecessors. 

Camden says: ‘‘ It is plain that the ancient Britons dealt in tin mines 
from the testimony of Diodorus Siculus, who lived in the reign of 
Augustus, and Timaus, the historian in Pliny, who tells us that the 
Britons fetched tin out of the Isle of Icta (the Isle of Wight), in their 
little wicker boats covered with leather. The import of the passage 
in Diodorus is that the Britons who lived in those parts dug tin out of 
a rocky sort of ground, and carried it in carts at low water to certain 
neighboring islands; and that from thence the merchants first trans- 
perted it to Gaul, and afterwards on horseback in thirty days to the 
springs of Eridanus, or the city of Narbona, as to a common mart. 
Asthicus too, another ancient writer, intimates the same thing, and 
adds that he had himself given directions to the workmen.” In the 
opinion of the learned author of the Britannica here quoted. and others 
who have followed him, the Saxons seem not to have meddled with 
tle ie or, according to tradition, to have employed the Saracens; 


178 DESCRIPTIONS OF MINERALS. 


for the inhabitants of Cornwall to this day call a mine that is given 
over working Attal-Sarasin, that is, the leavings of the Saracens. 

The Cornwall veins, or /odes, mostly run east and west, with a dip 
—hade, in the provincial dialect—varying from north to south; yet 
they are very irregular, sometimes crossing each other, and sometimes 
a promising vein abruptly narrows or disappears; or again they spread 
out into a kind of bed or floor. The veins are considered worth work- 
ing when but three inches wide. The gangue is mostly quartz, with 
some chlorite. Much of the tin is also obtained from beds of loose 
stones or gravel (called shodes),and courses of such gravel or tin débris 
are called streams, whence the name stream tin. The production of 
tin in Great Britain in 1883 was 9307 tons, valued at £785,189. Ger- 
many vields now not over 100 tons annually; and Austria, Italy, 
Spain, Russia, each less than this. 

The Australian mines are mainly in the New England district of 
Northern New South Wales, and the adjoining part of Queensland, 
having an area of 8500 sq. m.; a large part of the ore goes north 
through Queensland. The value of the tin exported in 1875 from 
Queensland was £103,740; in 1881, £2,168,790; in 1882, £560,590. 
New South Wales produced, in 1875, £561,311, corresponding to 6058 
tons of tin in ingots, besides 2022 tons of ore; in 1883 the amount was 
nearly 9000 tons. Tasmania produced in 1881 tin to the value of 
£375,775. Banca and Malacca, in 1882, produced over 15,000 tons. 

Tin is used in castings, and also for coating other metals, especially 
iron and copper. Copper vessels thus coated were in use among the 
Romans, though not common. Pliny says that the tinned articles 
could scarcely be distinguished from silver, and his use of the words 
incoquere and tncoctilia seems to imply, as a writer states, that the 
process was the same as for the iron wares of the present day, by 7m- 
mersing the vessels in melted tin. Its alloys with copper are mentioned 
on page 159. It is also used for coating copper. 

Tin is also used extensively as tinfoil ; but most of the modern tin- 
foil consists, beneath the surface, of lead, and is made by rolling out 
plates of lead coated with tin, an invention of Mr. J. J. Crookes, 
With quicksilver it is used to cover glass in the manufacture of mir- 
rors. ‘Tin oxide (dioxide), obtained by chemical processes, is employed, 
on account of its hardness, in making a paste (called ‘‘ putty of tin”) 
for polishing hard stones, for sharpening fine cutting instruments, 
and also to some extent in the preparation of enamels. The chlorides 
of tin are important in the precipitation of many colors as lakes, and 
in fixing and changing colors in dyeing and calico printing. The 
bisulphide has a golden lustre, and was termed aurum musivum, or 
mosaic gold, by the alchemists. It is much used for ornamental 
painting, for paper-hangings and other purposes, under the name of 
bronze powder. 


TITANIUM. 


Titanium occurs in nature combined with oxygen, form- 
ing titanium dioxide or titanic acid, and also in oxygen 
combinations with iron and calcium, and in some silicates. 
It has not been met with native. 


TITANIUM. 179 


The ores are infusible alone before the blowpipe, or nearly 
so. Their specific gravity is between 3:0 and 4:5. 


Rutile. 


Tetragonal; in prisms of four, eight, or more sides, with 
pyramidal terminations; often acicular and 
penetrating quartz; often twinned as in the 
figure and in other groupings (p.59; 1A 1=) 
123° 73’. Sometimes massive. Cleavage 
lateral, somewhat distinct. 

Color reddish brown to nearly red; streak 
very pale brown. Lustre submetallic-ada- 
mantine. ‘Transparent to opaque. Brittle. 
H. = 6-6°5. G. = 4:18-4°22; black, 4:24-4:25. 

Composition. TiO, = Oxygen 39, titanium 61 = 100. 
This composition is that also of octahedrite and brookite 
(next page); the species differ in crystallization and other 
physical characters. Sometimes contains iron, and has 
nearly a black color (Nigrine). B.B. alone unaltered ; 
with salt of phosphorus a colorless bead, which in the re- 
ducing flame becomes violet on cooling. 

Diff. The peculiar subadamantine lustre of rutile, and 
brownish-red color, in splinters much lighter red, are strik- 
ing characters. It differs from tourmaline, idocrase, and 
augite, by being unaltered when heated alone before the 
blowpipe; and from tin ore, in not affording tin with soda; 
from sphene in its crystals. 

Obs. Occurs in granite, gneiss, mica schist, syenyte, and 
in granular limestone. Sometimes associated with hema- 
tite, as at the Grisons. Occurs at Yrieix, France; Castile; 
Brazil; Arendal, Norway. 

In the United States, it occurs in crystals at Warren, 
Me.; Lyme and Hanover, N. H.; Barre, Windsor, Shel- 
burne, Leyden, Conway, Mass.; Monroe and Huntington, 
Ct.; near Edenville, Warwick, Amity, Kingsbridge, and 
in Hssex Co. at Gouverneur, N. Y.; in Chester Co., Pa.; 
District of Columbia, at Georgetown; Buncombe and Alex- 
ander Cos., N. C.; Lincoln and Habersham Cos., Ga.; 
Magnet Cove, Ark. 

Quartz crystal penetrated by long acicular crystals 
(Sagenite) are often very handsome when polished. A re- 
markable specimen of this kind was obtained in Northern 
Vermont, and less handsome ones are not uncommon; they 





180 DESCRIPTIONS OF MINERALS. 


are found in N. Carolina. Polished stones of this kind 
are called in France fléches d’amour (love’s arrows). 

This ore is employed in painting on porcelain, and quite 
largely for giving the requisite shade of color and enamel 
appearance to artificial teeth; some kinds make fine 
though nearly opaque gems. 

Octahedrite (Anatase). 'Tetragonal; in slender nearly transparent 
acute octahedrons; 1A1= 97° 51’: H. = 5°5-6; G. = 3°8-8°95; color 
brown. Dauphiny; the Tyrol; Brazil; Smithfield, R. I.; Brindle- 
town, Burke Co., N. C. 

Brookite. In thin hair-brown flat orthorhombic crystals; also in 
thick iron-black crystals, as in the variety called Arkansite ; H. = 
5°5-6. Dauphiny; Snowdon in Wales; Ellenville, Ulster Co., N. Y.; 
Paris, Me.; gold washings, N. C.; Magnet Cove, Ark. (Arkansite.) 

Pseudobrookite. In thin tabular brown to black crystals from 
Transylvania and Monte Dore. Much like brookite, but containing 
4°23 p. c. of Fe.Os. 

Perofskite. In cubic crystals, light yellow, brown, and black; 
formula (Ti, Ca),0;. Urals; Tyrol; Magnet Cove, Ark. 

Besides the ores here described, titanium is an essential constituent 
also of menaccanite (titanic iron), and of the silicates ttanite or sphene 
(p. 290), Ketthawite (p. 291), warwickite ; and occurs also in the zir- 
conia and yttria ores eschynite, wrstedite, and polymignite, and in some 
other rare species; sometimes in pyrochlore. 


COBALT. NICKEL. 


Cobalt has not been found native. The ores of cobalt 
are sulphides, arsenides, arseno-sulphides, an oxide, a car- 
bonate, a phosphate, and an arsenate; and nickel is often 
associated with cobalt in the sulphides and arsenides. The 
ores having a metallic lustre vary in specific gravity from 
6°2 to 7 2; are nearly tin-white or pale steel-gray, inclined 
to cgpper-red in color. ‘The ores without a metallic lustre 
have a clear red or reddish color, and specific gravity of 
nearly 3. Cobalt is often present also in arsenopyrite (or 
mispickel), and sometimes in pyrite. 

The ores of nickel are sulphides, arsenides, arseno-sulph- 
ides, and antimono-sulphides, a sulphate, carbonate, sili- 
cates, arsenate; and the metal is a constituent of several 
cobalt ores, and also often of pyrrhotite (magnetic pyrites). 
Specific gravity between 3 and 8; hardness of one, 3, but 
mostly between 5 and 6. ‘Those of metallic lustre resem- 
ble some cobalt ores; but they do not give a deep-blue color 
with ae Alloys of nickel and iron occur in meteorites 
(p. 189). 





COBALT. NICKEL. 181 


ScLpPuimeEs, ARSENIDES, ANTIMONIDES, TELLURIDES. 
Linnzite.—Cobalt Sulphide. Cobait and Nickel Sulphide. 


Isometric. In octahedrons and cubo-octahedrons; also 
massive. Color pale steel-gray, tarnishing copper-red. 
Streak blackish gray. H.=5°5. G. = 4°8-5. 

Composition. Oo,S, = Sulphur 42:0, cobalt 58°0 = 100; 
part of the cobalt replaced by nickel; copper sometimes 
present. Siegenite contains 30 to 40 per cent. of nickel. 
B.B. on charcoal yields sulphurous odor and a magnetic 
globule; often also arsenical fumes. 

Obs. From Sweden; Siegen, Prussia; Mine la Motte, 
Mo. (Sitegenite); Mineral Hill, Md. Sometimes called 
Cobalt pyrites. Carrollite is cobalt-copper pyrites. 


Millerite-—Nickel Sulphide. Capillary Pyrites. 


Rhombohedral. Usually in capillary or needle-like crys- 
tallizations; sometimes like wool; often in divergent tufts. 
Also in fibrous crusts; color brass-yellow, melining to 
bronze-yellow, with often a gray iridescent tarnish. Streak 
bright. Brittle. H.=3-3°5. G. = 5°65. 

Composition. NiS = Sulphur 35°6, nickel 64°4 = 100. 
In the open tube sulphurous fumes. B.B. on charccal fuses 
to a globule; after roasting, gives, with borax and salt of 
phosphorus, a violet bead in O.F., which in R.F. becomes 
gray from reduced metallic nickel. 

Obs. Krom Joachimstahl, Przibram, Riechelsdorf; Sax- 
ony; Cornwall; at the Sterling Mine, Antwerp, N. Y.; at 
the Gap Mine, Lancaster Co., Pa.; at St. Lonis, Mo., in 
capillary forms, and sometimes wool-like, in cavities in 
magnesian limestone; Nevada. A valuable ore of nickel. 

Beyrichite. WHexagonal?; a nickel sulphide with Ni 5*°79 p. c. 

Polydymite. In isometric octahedrons; brilliant metallic; gray ; 
nickel sulphide. Griinau, Westphalia. 


Smaltite.—Cobalt Glance. Chlcanthite. 


Isometric. In octahedrons, cubes, dodecahed*ens, and 
other forms; see Figs. 1, 2, 3, page 18, and 17, 27, page 
21. Cleavage octahedral, somewhat distinct. Also reticu- 
lated; often massive. 

Color tin-white, sometimes inclining to steel-gray Streak 
erayish black. Brittle. Fracture granular and uneven, 
H.=5'5-6. G. =6-4-6°9, mostly; also 7:2. 


182 DESCRIPTIONS OF MINERALS. 


Composition. (Co, Ni) As,; the ore being either a cobalt 
arsenide, or cobalt-nickel arsenide; and graduating into the 
nickel arsenide called Chloanthite. ‘The cobalt in the ore 
varies from 23°5 per cent. to none; iron often replaces 
part of the other metals. 

In the closed tube gives metallic arsenic; in the open 
tube, a white sublimate of arsenous oxide, and sometimes 
traces of sulphurous acid. B.B. on charcoal an arsenical 
odor, fuses to a globule which gives reaction for iron, co- 
balt, and nickel. 

Diff. Arsenopyrite (mispickel) is white like smaltite, 
but yields sulphur as well as arsenic, and in a closed tube 
affords the arsenic sulphides, orpiment and realgar. 

Obs. Usually in veins with ores of cobalt, silver, and 
copper. Occurs in Saxony, especially at Schneeberg ; also 
in Bohemia, Hessia, and Cornwall. In the U. States, 
found sparingly i in gneiss, with niccolite, at Chatham, Ct.; 
in Gunnison Co., Col. 


Cobaltite. 


Isometric. Crystals like those of pyrite, but silver-white 
with a tinge of red, or inclined to steel- sry Streak gray- 
ish black. Brittle. H.=5°5. G. = 6-6°3 

Composition. CoS, + CoAs, = CoAsS = ‘Arsenic 45° 25 
sulphur 19°3, cobalt 35°5 = 100, but often with much iron 
and occasionally a little copper. Unaltered in the closed 
tube; but in the open tube, yields sulphurous fumes and a 
white sublimate of arsenous oxide. B.B. on charcoal yields 
sulphur and arsenic and a magnetic globule; with borax a 
cobalt-blue globule. 

Diff. Unlike smaltite affords sulphur, and has a reddish 
tinge in its white color. 

Obs. From Sweden, Norway, Siberia, and Cornwall. 
Most abundant in the mines of Wehna in Sweden, first 
opened in 1809. 


Niccolite.—Copper Nickel. Arsenical Nickel. 


Hexagonal. Usually massive. Color pale copper-red. 
Streak pale brownish-red. Lustre metallic. Brittle. H. = 
5-5°5. = 7°35-7°67, 

Composition. NiAs = Nickel 44, and arsenic 56; part 
of the arsenic may be replaced by antimony. B.B. gives 
off arsenical fumes, and fuses to a pale globule, which 


COBALT. NICKEL. 183 


darkens on exposure. Assumes a green coating in nitric 
acid, and is dissolved in aqua-regia. Ariée is an antimo- 
nial variety from Balen, Pyrenees. 

Diff. Distinguished from pyrite and linneite by its pale 
reddish shade of color, and also its arsenical fumes, and 
from much of the latter by not giving a blue color ‘With 
borax. None of the ores of silver with a metallic lustre 
have a pale color, excepting native silver itself. 

Obs. Accompanies cobalt, silver, and copper ores in the 
mines of Saxony, and other parts of Europe; also sparingly 
in Cornwall. Found at Chatham, Ct., in gneiss, associated 
with white nickel or cloanthite; in Churchill Co., Neyv., 
abundant, near Lovelock’s station, on the Central Pacific 
Tie 


Skutterudite, Cobalt arsenide, CoAs;. Skutterud, Norway. 

Safflorite (Spathiopyrite). Cobalt-iron arsenide; orthorhombic ; tin- 
white. Bieber, Germany. 

Breithauptite or Antimonial Nickel. UHexagonal; pale copper-red, 
inclining to violet; H. = 55-6; G. = 7°54; NiSb = Antimony 67°8, 

nickel 33-2 = 100. Andreasbers. 
Gersdorfite (Nickel glance). A nickel arsenosulphide; NiS. ite NiAs, 
= NiAsS = Arsenic 45°'5, sulphur 19°4, nickel 35°1, but varying much 
in composition : sulphur-white to steel- -gray; H. = 55; G. = 5°6-6°9. 
Loos, Sweden ; the Hartz; Styria ; Thuringia. Sommarugaite is an 
auriferous kind from Hungary. 

Ullmannite or Nickel Stibine. An antimonial nickel sulphide, con- 
taining 25 to 28 p. c. of nickel; steel-gray, inclining to silver-white; in 
cubes, ~ and massive; H. = 5-5: Bs G, = 6°25-6°'5. Duchy of Nassau. 

Grinauite or Bismuth Nickel. A sulphide containing 31 to 38°5 of 
sulphur, 10 to 14 per cent. of bismuth, with 22 to 40°7 of nickel ; 
light steel-gray to silver-white; often tarnished yellowish; H. = 4°5; 
G. = 5°13, Altenkirchen, Prussia. 

pai Nickel telluride; reddish white. Calaveras and Bowlder 
Cos., Cal. 


OXIDE. 
Asbolite.—Earthy Cobalt. Black Cobalt Oxide. 


Earthy, massive. Color black or blue-black. Soluble 
in muriatic acid, with an evolution of fumes of chlorine. 

Obs. Occurs in an earthy state mixed with oxide of man- 
ganese as a bog ore, or secondary product. Abundant at 
Mine La Motte, Missouri, and also near Silver Bluff, South 
Carolina. The analyses vary in the proportion of oxide of 
cobalt associated with the manganese, as the compound is 
amere mixture. Sulphide of cobalt occurs with the oxide. 


e 


184 DESCRIPTIONS OF MINERALS. 


The Carolina ores afforded cobalt oxide 24, manganese 
oxide 76. The ore from Missouri, as analyzed by B. Silli- 
man, afforded 40 per cent. of cobalt oxide, with oxides of 
nickel, manganese, iron and copper. 

This ore has been found abroad in France, neercg 
Austria, and England. 

The ore is purified and made into smalt, for the arts. 

Heterogenite. Black; reniform; contains 78 p. c. cobalt oxide, and 
21°33 of water. Schneeberg. 


Heubachite. Mixture of oxides of cobalt, nickel and iron, with 
water. 


ARSENATES, SULPHATES, CARBONATES, SILICATES. 
Erythrite.—Cobalt Bloom. Hydrous Cobalt Arsenate. 


Monoclinic. In oblique crystals having a highly perfect 
cleavage, like mica; lamine flexible in one direction. Also 
as an incrustation; in reniform shapes; stellate. . 

Color peach-red, crimson-red, rarely grayish or green- 
ish; streak a little paler, the dry powder lavender-blue, 
Lustre of lamine pearly; earthy varieties without lustre. 
Transparent to subtranslucent. H.=1°5-2. G. = 2°95. 

Composition. Co,O,As, + 8aq (or 3CoO + As,O, + 8aq) 
= Arsenic acid 38° 4, oxide of cobalt 37° 6, water 24-0, BB. 
on charcoal, arsenical fumes and fuses; a blue glass with 
borax. 

The earthy ore is sometimes called peach-blossom ore, 
from its color; and red cobalt ochre. Kottigite isa kind 
containing zinc. 

Diff. Resembles red antimony, but that species wholly 
volatilizes before the blowpipe. Red copper ore differs in 
color and in giving a blue glass with borax; moreover, the 
color of the copper ore is more sombre. 

Obs. Occurs with ores of lead and silver, and other cobalt 
ores, at Schneeberg, Saxony; Saalfield, Thuringia; Riech- 
elsdorf, in Hessia; Dauphiny; Cornwall; Cumberland; near 
Lovelock’s station on U. P. R. ies Nevada; Compton, Cal. 

Valuable as an ore of cobalt when abundant. 


Roselite. Cobalt arsenate; rose-red; triclinic. Schneeberg. 

Cobaltomenite. Cobalt selenite. Cacheuta, S. A. 

Annabergite. Nickel arsenate; apple-green. Allemont, Dauphiny; 
Annaberg; Riechelsdorf ; Nevada. 

Cabrerite. Hydrous nickel arsenate. Laurium, Greece. 

Bieverite (Cobalt Vitriol). Fiesh-red, rose-red; taste astringent; 


COBALT. NICKEL 185 


Co0.S + Yaq (or CoO +80; + Yaq) = Sulphuric acid 28°4, cobalt 
oxide 25°5, water 46:1. Bieber, near Hanau; Salzburg; Chili. 

Morenosite (Nickel Vitriol). NiO.,S-+ Taq; apple-green, greenish. 

Lindackerite. Hydrous nickel-copper arsenate. 

Zaratite (Emerald Nickel). Incrusting, minute globular or stalac- 
titic; bright emerald-green; lustre vitreous; transparent or nearly so; 
H. = 3-3°25; G. = 2°5-2°7; nickel carbonate, containing nearly 30 
per cent. of water; B. B. infusible alone, but loses its color. With 
chromite on serpentine, Lancaster Co., Pa. 

Remingtonite. Hydrous cobalt carbonate; rose-colored. Finks- 
burg, Md. 

Spherocobaltite. Cobalt carbonate, CoO;C (or CoO + CO:); black 
to red. Saxony. 

Nicket Srmicates. Genthite isa hydrous magnesium-nickel sili- 
cate, pale apple-green, yielding in one analysis 30 per cent. of nickel 
oxide; from Tex.s, Lancaster Co., Pa., and other localities. Rdttisite, 
from Réottis, Voigtland, is similar. Pmelite isan impure apple-green 
silicate, affording in one case 15°6 per cent. of nickel oxide. Alipite 
and Avalite are similar; so also Garnierite (and Noumette), from New 
Caledonia, and worked there for nickel. A similar ore occurs 8 m. 
from Canonville in 8. Oregon, in serpentine. 


General Remarks.—The two arsenical ores of cobalt afford the 
greater part of the cobalt of commerce. The earthy oxide when 
abundant is a profitable source of the metal. Erythrite (Cobalt 
Bloom) occurs abundantly with other cobalt ores at its localities in 
Saxony, Thuringia and Hesse Cassel. Arsenopyrite (mispickel) yields 
at times 5 to 9 per cent. of cobalt. Nearly all the cobalt used in the 
U. States is imported. Mine La Motte afforded $12,500 worth in 
1882, and the works at Camden, Pa., about 3 times thisamount. The 
value of the metal is a little Jess than $3 a pound. 

Cobalt is never employed in the arts in a metallic state, as its alloys 
are brittle and unimportant. It is chiefly used for painting on porce- 
lain and pottery, and for this purpose it is mostly in the state of an 
oxide, or the silicated oxide called smalt and azure. Thenard’s blue, 
or cobalt ultramarine, is made on the large scale by heating a mixture 
of phosphate or arsenate of cobalt and alumina. Zajfre is an impure 
oxide obtained in the calcining of the ore with twice its weight of 
sand; and from it the smalt and azure are produced. 

Nickel is worked in Germany, Austria, Russia, Sweden, England, 
United States, and New Caledonia. It is obtained largely from the 
copper nickel (niccolite) and chloanthite, or from an artificial product 
called spezss (an impure arsenide), derived from roasting ores of cobalt 
containing nickel; from siegenite (or nickel-linneite), a sulphide of 
cobalt and nickel; from millerite, in part; from the apple-green sili- 
cate; and largely from pyrrhotite or ‘‘ magnetic iron pyrites.” At 
the Gap Mine, near Lancaster, Pa., the ore is pyrrhotite with miller- 
ite; and the nickel produced from the mine in 1884 was 64,550 lbs.; 
this was smelted at the American Nickel Works, at Camden, N. J., 
the only nickel works in the U. States. In Missouri, the ore is siege- 
nite; in New Caledonia, chiefly the silicate. 

Nickel often occurs with chrome ores in serpentine rocks; it also 


186 DESCRIPTIONS OF MINERALS. 


occurs in meteoric iron, forming an alloy with the iron, which is char- 
acteristic of most meteorites. The proportion sometimes exceeds 20 
per cent. 

As nickel does not rust or oxidize (except when heated), it is supe- 
rior to steel for the manufacture of many philosophical instruments, 
An alloy of copper, nickel, and zinc (one-sixth to one-third nickel), 
constitutes the German silver, or argentane. 

‘‘German silver’ is not a very recent discovery. In the reign of 
William III. an act was passed making it felony to blanch copper in 
imitation of silver, or mix it with silver for sale. ‘‘ White copper” 
has long been used in Saxony for various small articles; the alloy 
employed is stated to consist of copper 88°00, nickel 8°75, sulphur 
with a little antimony 0°75, silex, clay, and iron 1°75. <A similar 
alloy is well known in China, and is smuggled into various parts of 
the East Indies, where it is called packfong. It has been sometimes 
identified with the Chinese twtenague. M. Meurer analyzed the white 
copper of China, and found it to consist of copper 65°24, zine 19°52, 
nickel 13, silver 2-5, with a trace of cobalt and iron. Dr. Fyfe ob- 
tained copper 40°4, nickel 31°6, zinc 25°4, and iron 2°6. It has the 
color of silver, and is remarkably sonorous. It is worth in China 
about one fourth its weight of silver, and is not allowed to be carried 
out of the empire. 

An alloy of 75 per cent. copper and 25 per cent. nickel is the mate- 
rial of the United States cent. Switzerland, Belgium, Germany, 
Mexico, and Jamaica also use a nickel alloy for coins. 

Nickel is largely used at the present time for nickel-plating by 
electro-deposition. The value of the metal in commerce rose in the 
years 1870 to 1875, from $1.25 to $3.00 per pound ; but since 1880 it 
has been $1 to $1.10. 


URANIUM. 


Uranium ores have a specific gravity not above 10, and a 
hardness below 6. The ores are either of some shade of light 
green or yellow, or they are dark brown or black and dull, 
or submetallic and without a metallic lustre when powdered. 
They are not reduced when heated with carbonate of soda; 
and the brown or black species fuse with difficulty on the 
edges or not at all. 


Uraninite.—Pitchblende. Uranium Oxide. 


Isometric. In octahedrons and related forms. Also mas- 
sive and botryoidal. Color grayish, brownish, or velvet- 
black. Lustre submetallic or dull. Streak black. Opaque. 
H. =5'5. G. =, when unaltered, 9°2-9°3 (from Branch- 
ville). 

Geico Branchville crystals, U 81°50, O 13°47, 
Pb 3:97, Fe 0°40, H,O 0°88 =100°22. Mineral usually 
altered and impure, with G. 64-8. B.B. infusible; a gray 


URANIUM. 187 


scoria with borax. Dissolves slowly in nitric acid when 
powdered. 

Obs. Occurs in veins with ores of lead and silver in Sax- 
ony, Bohemia, and Hungary; also in the tin-mines of Corn- 
wall, near Redruth. In the United States, at Branchville, 
in brilliant octahedrons; very sparingly at Middletown and 
Haddam, Ct.; in N. Carolina; on the north side of Lake 
Superior (Coracite); in Gilpin Co., near Central City, Col., 
with torbernite and other uranium ores (common results of 
its alteration), where, in 1872, a large body of it was thrown 
out of a shaft, and 3 tons sold in England for $1.50 per 
pound. 

The oxides of uranium are used in painting upon porce- 
lain, yielding a fine orange in the enamelling fire, and a black 
color in that in which the porcelain is baked. Bohemia is 
the chief source of it. 

Clevette. Hydrated oxide of uranium, iron, erbium, cerium, 

trium; isometric, like spinel. Norway. SBréggerite is related; from 
Norway. 

Gummite. An amorphous uranium ore, looking like gum, of a red- 
dish or brownish color; a hydrous uraninite. Johanngeorgenstadt; 
N. Carolina. 

Hliasite. Like gummite, more or less resin-like in aspect; reddish- 
brown to black. Elias Mine, Joachimstahl. 

Hatchettolite. ydrous niobo-tantalate of uranium; in isometric 
octahedrons ; resembles pyrochlore; G.=4°76-4°84. Mitchell Co., 


North Carolina. 
Blomstrandite. Hydrous titano-niobate; black. Sweden. 


Torbernite.—Uranite. Chalcolite. Uran-Mica. 


Tetragonal. In square tables, thinly foliated parallel to 
the base, almost like mica; lamine brittle. 

Color emerald and grass-green; streak a little paler. 
Lustre of lamin pearly. ‘Transparent to subtranslucent. 
H. = 2-2°5. G. =3°3-3°6. 

Composition. A uranium-copper phosphate, consisting if 
pure of Phosphorus pentoxide 15:1, uranium trioxide 61:2, 
copper oxide 8°4, water 15°3 = 100. B.B. fuses toa blackish 
mass, and colors the flame green. 

Diff. The micaceous structure, bright green color and 
square tabular form of the crystals are striking characters. 

Obs. Occurs with uranium, silver and tin ores. It is 
found at St. Symphorien, in splendid crystallizations, near 
Redruth and elsewhere in Cornwall; in the Saxon and 
Bohemian mines; in North Carolina, 


188 DESCRIPTIONS OF MINERALS. 


Autunite. Similar to torbernite and often occurring with it; 
color bright citron-yellow; a uranium-calcium phosphate; G. = 3-3°2. 
Near Autun in France; sparingly, Portland, Middletown ; good at 
Branchville, Ct.; Acworth, N. H.; Chesterfield, Mass.; and in N. 
Carolina. 

Uranospinite is an autunite containing arsenic instead of phos- 
phorus; and Zeunerite, a torbernite containing arsenic instead of phos- 

horus. 

5 Phosphuranylite. Hydrous uranium-lead phosphate; lemon-yellow. 
Mitchell Co., N. C. 

Samarskite, Huxenite, Annerédite. See p. 221. 

Johannite or Uranvitriol. A uranium sulphate; fine emerald green; 
taste bitter. Bohemia. Uranochalcite, Medijdite, Zippeite, Voglianite, 
Uraconite, are other uranium sulphates. 

Trégerite and Walpurgite are uranium arsenates. Voglite and Liebig- 
ite are uranium carbonates. 

Uranocircite (Baryturanite) is a hydrous barium-uranium phosphate. 
Uranothallite is a hydrous uranium-lime carbonate; and Schrdéckerin- 
gite is similar. 

Uranotil. A hydrous uranium-calcium silicate; G. =3°8-3°9; 
Saxony; Mitchell Co., N.C. Uvranopilite,a hydrous calcium-ura- 
nium silicate; from Saxony. Randiie, a doubtful yellow uranium 
compound; near Philadelphia, Pa. Uranothorite is a thorite contain- 
ing uranium; from the Champlain iron region, N. Y. 


IRON. 


Tron occurs native, and ailoyed with nickel in meteoric 
iron. Its most abundant ores are the oxides and sulphides. 
It is also found combined with arsenic, forming arsenides 
and sulpharsenides ; with oxygen and other metals, as chro- 
mium, aluminum, magnesium ; and in the condition of sul- 
phate, phosphate, arsenate, niobate, tantalate, silicate, and 
carbonate, of which the last is an abundant and valuable ore. 
Its ores are widely disseminated. ‘The oxides and silicates 
are the ordinary coloring ingredients of soils, clays, earth, 
and many rocks, tingeing them red, yellow, dull green, brown, 
and black. 

The ores have a specific gravity below 8, and the ordinary 
workable ores seldom exceed 5. Many of them are infusible 
before the blowpipe, and nearly all minerals containing iron 
become attractable by the magnet after heating, B.B. in 
the inner flame, when not so before. By their difficult 
fusibility, the species with a metallic lustre are distinguished 
from ores of silver and copper, and also more decidedly from 
these and cther ores by blowpipe reaction. 


IRON. 189 


Native Iron. 


Isometric. Usually massive with octahedral cleavage. 

Color and streak iron-gray. Fracture hackly. Malleable 
and ductile. H.=4°5. G.=73-7°8. Acts strongly on 
the magnet. 

Obs. Native iron occurs in grains disseminated through 
some doleryte, basalt, and other related igneous rocks (as 
in Connecticut); and in Greenland, in very large masses in 
such igneous rocks, the largest weighing over a ton. It is 
suggested by J. Lawrence Smith, that the iron was re- 
duced by means of carbohydrogen vapors, taken into the 
rock from carbonaceous rocks passed through on the way to 
the surface. 

It is a constituent of nearly all meteorites, and the chief 
ingredient in a large part of them; and in this state it is 
with a rare exception alloyed with nickel, and with traces 
of cobalt and copper. The Texas meteorite, of Yale Col- 
lege, weighs 1635 pounds; the Pallas meteorite, now at 
Vienna, originally 1600; but one in Mexico, the San Gre- 
gorio meteorite, is stated to weigh five tons; and one in the 
district of Chaco-Gualamba, 8. A., nearly fifteen tons. 
Meteoric iron often has a very broad crystalline structure, 
long lines and triangular figures being developed by putting 
nitric acid on a polished surface. ‘The coarseness of this 
structure differs in different meteorites, and serves to dis- 
tinguish specimens not identical in origin. Nodules of 
troilite (FeS), and schreibersite (iron phosphide) are com- 
mon in iron meteorites. Meteoric iron may be worked like 
ordinary malleable iron. The nickel diminishes the ten- 
dency to rust. But some kinds contain iron chloride, or 
are open in texture, and rust badly. Chamasite, Tenite, 
Oktibehite, Edmonsonite, are names given to different alloys 
of nickel and iron found in meteorites. 


SULPHIDES, ARSENIDES, TELLURIDES, CHLORIDES. 
Pyrite.—Iron Pyrites. Iron Disulphide. 


Isometric. Usually in cubes, the striz of one face at right 
angles with those of either adjoining face, as in Fig. 1. Also 
Figs. 2 to 7; also Figs. 8 to 15 on page 20. Fig. 6, a pentag- 
onal dodecahedron, is a common form. Occurs also in imi- 
tative shapes, and massive. 


190 DESCRIPTIONS OF MINERALS. 


Color brass-yellow ; streak brownish-black. Lustre often 
splendent metallic. Brittle. H. = 6-6°5, will strike fire 
with steel. G. = 4°8-5°2; purest 5°1-0°2. 

Composition. FeS, =Sulphur 53°3, iron 46°7=100. 






: 


B.B. on charcoal gives off sulphur, and ultimately affords 
a globule attractable by the magnet. 

Pyrite often contains a minute quantity of gold, and is 
then called auriferous pyrite. See under Gold. Nickel, 
cobalt, and copper occur in some pyrite. 

Diff. Distinguished from copper pyrites in being too hard 
to be cut by a knife, and also in its paler color. ‘The ores 
of silver at all resembling pyrite are steel-gray or nearly 
black; and besides, they are easily scratched with a knife 
and quite fusible. Gold is sectile and malleable. 

Obs. Pyrite is one of the most common of ores. Occurs 
in rocks of all ages. Cornwall, Elba, Piedmont, Sweden, 
Brazil, and Peru have afforded magnificent crystals. Alston 
Moor, Derbyshire, Kongsberg in Norway, are well-known 
localities. It has also been observed in the Vesuvian lavas, 
and in many other igneous rocks. It is mined largely in 
Spain and Portugal, particularly at the Rio Tinto mine. 

Fine crystals have been met with at Rossie, N. Y., and 
at many other places in that State ; also in each of the New 
England States and in Canada ; in New Jersey, Pennsylvania, 


IRON. 191 


Virginia, North Carolina, Georgia, in Colorado, Wyoming, 
and the States west. It occurs in all gold regions, and is 
one source of gold. A vein is worked in Rome, near Char- 
lemont, Mass.; several in Louisa Co., Va.; in Georgia; 
at Capelton, Canada. 

This species is of high importance in the arts, although 
not affording good iron on account of the difficulty of sep- 
arating all the sulphur. It affords the greater part of the 
sulphate of iron (green vitriol or copperas) and sulphuric 
acid (oil of vitriol) of commerce, and also a considerable 
portion of the sulphur and alum. ‘To make the sulphate 
the pyrites are sometimes heated in clay retorts, by which 
about 17 per cent. of sulphur is distilled over and collected. 
The ore is then thrown out into heaps, exposed to the at- 
mosphere, when a change ensues by which the remaining 
sulphur and iron become through oxidation sulphate of iron. 
The material is lixiviated, and partially evaporated, prepar- 
atory to its being run off into vats or troughs to crystallize. 
In other instances, the ore is coarsely broken up and piled 
in heaps and moistened. Fuel is sometimes used to com- 
mence the process, which afterwards the heat generated 
continues. Decomposition takes place as before, with the 
same result. Cabinet specimens of pyrite, especially the 
granular or amorphous masses, often undergo a spontane- 
ous change to the sulphate, particularly when the atmos- 
phere is moist. 

Pyrite, owing to its tendency to oxidation, and its very 
general distribution in rocks of all kinds and ages, is one of 
the chief sources of the disintegration and destruction of 
rocks. No granite, sandstone, slate, or limestone, contain- 
ing it is fit for architectural purposes or for any outdoor 
use. The same destructive effects come from pyrrhotite 
and marcasite, which also are widely diffused. 

The name pyrites is from the Greek pur, fire; because, 
as Pliny states, ‘‘there was much fire in it,” alluding to 
its striking fire with steel. This ore is the mundic of 
miners. 





Marcasite or White tron pyrites. Like pyrite in composition, but 
orthorhombic; J A J= 106° 86’; color a little paler; more liable to de- 
composition; hardness the same; G. = 4°6-4'85. Radiated pyrites, He- 
patic pyrites, Cockscomb pyrites (alluding to its crested shapes), and 
Spear pyrites, are names of some of its varieties. In crystals at War- 
wick and Phillipstown, N. Y.; massive at Cummington, Mass. ; Mon- 
roe, Trumbull, East Haddam, Ct.; Haverhill, N. H. 


192 DESCRIPTIONS OF MINERALS. 


Pyrrhotite.—Magnetie Pyrites. Iron Sulphide. 


Hexagonal. In tabular hexagonal prisms, and massive. 

Color between bronze-yellow and copper-red ; streak dark 
grayish black. Brittle H.=3°5-4:°5. G@. = 4:5-4°65. 
Shightly attracted by the magnet. Liable to speedy tarnish. 

Composition. Fe,S,=Sulphur 39:5, iron 60°. It is 
often a valuable ore of nickel, containing sometimes 3 to 5 
er cent. of this metal. B.B. on charcoal in the outer flame 
it is converted into red oxide of iron. Inthe inner flame it 
fuses and glows, and affords a black magnetic globule, which 
is yellowish on a surface of fracture. 

Diff. Its inferior hardness and shade of color, and its 
magnetic quality distinguish it from pyrite; and its pale- 
ness of color from chalcopyrite or copper pyrites. 

Obs. Found at Kongsberg, Norway; Andreasberg in the 
Hartz; massive in Cornwall; Saxony; Siberia; the Hartz; 
also at Vesuvius. 

In the United States it is met with at Trumbull Al 
Monroe, New Fairfield, and Litchfield, Ct.; New Marlboro 
and elsewhere, Mass. ; Strafford and Shrewsbury, Vt.; Cor- 
inth, N. H.; Brewster, etc., N. Y.; Lancaster, Pa., where 
it is worked for nickel ; Canada, at "Elizabethtown, i in crys- 
tals. Itis used for making green vitriol and sulphuric acid, 
like pyrite. 

Troilite. Like pyrrhotite, but having the formula FeS ; occurs 


only in meteorites. 
Schreibersite. Iron-nickel phosphide. In meteorites, 


Arsenopyrite.—Mispickel. Arsenical Iron Pyrites. 


Orthorhombic; ZA 7=111° 40’ to 112°. In rhombic 
prisms, with cleavage parallel to J. 
Crystals sometimes elongated hori- 
zontally, producing a rhombic prism 
of 100° nearly, with Z and J the end 
planes. Also massive. 

Color silver-white. Streak dark 
grayish black. Lustre shining. 
Brittle. H.=5°5-6. G.=5°67- 
6:3. 

Composition. KeAsS = Arsenic 
46°0, sulphur 19°6, iron 34°4= 200. <A cobaltie variety 
contains 4 to 9 per cent. of cobalt in place of part of the 





IRON. 193 


iron; Danaite of New Hampshire consists of Arsenic 41°4, 
sulphur 17:8, iron 32°9, cobalt 6°5. B.B. affords arsenical 
fumes, and a globule of iron sulphide attractable by the 
magnet. In theclosed tube a sublimate of arsenic sulphide. 
Gives fire with asteel and emits a garlic odor. 

Diff. Resembles arsenical cobalt, but is much harder, it 
giving fire with steel; differs also in yielding a magnetic 
globule B.B. 

Obs. Found mostly in crystalline rocks, and common 
with ores of silver, lead, iron, or copper. Worked for its 
arsenic, and sometimes also for cobalt and gold. Abundant 
at Freiberg, Munzig, and elsewhere in Europe, and also in 
Cornwall, England. 

In crystals, at Franconia, Jackson, and Haverhill, N. H.; 
at Blue Hill Bay, Corinth, Newfield, and Thomaston, 
Me.; at Waterbury, Vt.; massive at Worcester and Sterling, 
Mass.; at Franklin, N. J.; in Lewis, Essex Co., and near 
Edenville and elsewhere in Orange Co., in Kent, Putnam 
Co., N. Y.; at Deloro, Canada, in crystals, and worked for 
arsenic. 


Leucopyrite. Arsenical iron FeAs,. Resembles the preceding in 
color and in its crystals; has less hardness and higher specific gravity; 
H. = 5-5'5; G. = 6°8-8°71. Contains arsenic 72°8, iron 27°2, with some 
sulphur. From Styria, Silesia, and Carinthia. Nickeliferous from 
Gunnison Co., Col. 

Léllingite. Another iron arsenide, Fe.As; = Arsenic 66°8, iron 33°'2; 
G. = 6°2-7°45. 

Berthierite. An iron sulphantimonite. 

Orileyite. A doubtful steel-gray iron-copper arsenide. _Burmah, 

Ferrotellurite. Iron tellurite, FeO.Te; tufts of minute prisms ; 
yellow, greenish. Keystone Mine, Col. 

Lawrencite. Tron protochloride. The Greenland native iron, and 
one cause of its rapid oxidization. Named after J. Lawrence Smith, 
Stagmatite is the same. 
~ Molysite. Tron chloride, FeCls. Vesuvius. 

Kremersite. Tron-potassium-amm nium chloride. Vesuvius, 

Erythrosiderite. _Hydrous iron-potassium chloride. Vesuvius, 
Douglassite. 

Siderazote. Iron nitride, Fe;N.2; an incrustation ; lustre steel-like. 
Mt. Etna. 


OXIDES. 
Hematite.—Specular Iron Ore. Iron Sesquioxide. 


Rhombohedral; R A Rk = 86° 10’ (Fig. 1). Crystals oc- 
casionally thin tabular. Cleavage usually indistinct, Often 
13 


194 DESCRIPTIONS OF MINERALS. 


massive granular; sometimes lamellar or micaceous. Also 
pulverulent and earthy. | 

Color dark steel-gray or iron-black. Lustre when crys- 
tallized splendent. Streak-powder cherry-red or reddish- 


R 


brown. ‘The metallic varieties pass into a red earthy ore 
called red ochre, having none of the external characters of 
the crystals, but like them when they are pulverized. G. = 
4°5-5°3. Hardness of crystals 5°5-6'5. Sometimes slightly 
attracted by the magnet. 


VARIETIES, 


Specular iron. Lustre perfectly metallic. 

Micaceous iron. Structure foliated. 

Red hematite. Submetallic, or unmetallic, brownish red. 
_ Led ochre. Soft and earthy, and often containing clay. 

ecwendted chalk. More firm and compact than red ochre, and 

of a fine texture. 

Jaspery clay iron. A hard impure siliceous clayey ore, 
and having a brownish red jaspery look and compactness. 

Clay iron stone. 'The same as the last, the color and ap- 
pearance less like jasper. But this is one variety only of 
what is called ‘‘ clay iron stone,” a name covering also a re- 
lated variety of siderite and limonite. 

Lenticular argillaceous ore. An oolitic red ore, consist- 
ing of small flattened grains. 

Martite is hematite in octahedrons, derived, it is supposed, 
from the oxidation-of magnetite. 

Composition. EeO* = Oxygen 30, iron 70 =100. B.B. 
alone infusible ; in the inner flame becomes magnetic. 7 

Diff. The red powder of this mineral, and the magnetism 
which is so easily induced in it by the reduction flame dis- 
tinguish hematite from all other ores. The word hematite, 
from the Greek haima, blood, alludes to the color of the 
powder. ‘lhe powder of magnetite is black. 


IRON. . 195 


Obs. Occursin crystalline and stratified rocks of all ages. 
The more extensive beds abound in Archean rocks; while the 
argillaceous varieties occur in stratified rocks, being often 
abundant in coal regions and among other strata. Crys- 
tallized specimens are found also in some lavas, as a volcanic 
product. 

Splendid crystallizations of this ore come from Elba, whose 
beds were known to the Romans; also from St. Gothard ; 
Arendal, Norway; Longbanshyttan, Sweden ; Lorraine and 
. Dauphiny ; Brazil (martite in part). Etna and Vesuvius 
afford handsome specimens. 

In the United States an abundant ore. The two Iron 
Mountains of Missouri, situated 90 miles south of St. Louis, 
consist mainly of this ore, piled ‘‘in masses of all sizes from 
a pigeon’s egg to a middle-sized church ;” one 300 feet high, 
the other, the ‘‘ Pilot Knob,” 700 feet. Large beds occur 
in Essex, St. Lawrence, and Jefferson Cos., N. Y.; at Mar- 
quette, Mich.; the micaceous variety, at Hawley, Mass., 
Piermont, N. H., and in Stafford County, Va.; lenticular 
argillaceous ore abundantly in Oneida, Herkimer, Madison, 
and Wayne Cos., N. Y., constituting one or two beds of the 
Clinton group (Upper Silurian), in a compact sandstone ; 
and the same is found in Pennsylvania and south to Ala- 
bama, and also in Wisconsin ; it contains 50™~per cent. of 
oxide of iron, with about 25 of carbonate of lime and more 
or less magnesia and clay. The coal region of Pennsylvania 
affords abundantly the clay iron ores, but they are mostly 
either the argillaceous carbonate or limonite. 

Much of the Marquette ore is martite; and the Cerro de 
Mercado, of Mexico, is spoken of as a mountain of mar- 
tite. 

Valuable as an iron ore, though less easily worked when 
pure and metallic than the magnetic and hydrous ores. Pul- 
verized red hematite is used for polishing metal. Red chalk 
is a well-known material for red pencils. 


Menaccanite.—I]menite. Titanic Iron. Washingtonite. 


Rhombohedral ; R A k= 85°31’. Often in thin plates 
or seams in quartz; also in grains, Crystals sometimes 
very large and tabular. 

Color iron-black. Streak submetallic. Lustre metallic or 
submetallic. H.=5-6. G.=4:'5-5. Acts slightly on 
the magnetic needle. 


196 DESCRIPTIONS OF MINERALS. 


Composition. Like that of hematite, except that part of 
the iron is replaced by titanium ; the amount replaced is 
very variable. Infusible alone before the blowpipe. 

Diff. Near hematite, but its powder is not red. 

Obs. In Warwick, Amity, and Monroe, Orange Co., N.Y. 
Crystals, an inch in diameter; near Edenville and Green- 
wood Furnace ; at South Royalston and Goshen, Mass.; at 
Washington, South Britain, and Litchfield, Ct.; at Westerly, 
R.I.; Magnet Cove, Ark ; in Canada. 

It is of no value in the arts, and is a deleterious constitu- 
ent of many iron ores. 


Magnetite.—Magnetic Iron Ore. 
Isometric. Often in octahedrons (Fig. 1), and dodecahe- 


2. 


drons (Fig. 2). Cleavage oc- 
1. tahedral; sometimes distinct. 
Also granularly massive. 
Occasionally in dendritic 
forms between the folia of 
mica. 
Color iron-black. Streak 
black. Brittle. H.=5°5-6°5. 
G.=5:'0-5'1. Strongly at- 
attracted by the magnet, and sometimes having polarity. 

Composition. FeFeO, = FeO+ FeO, = Oxygen 27°6, iron 
72°4=100. Infusible before the blowpipe. Yieldsa yellow 
glass when fused with borax in the outer flame. 

Diff. The black streak and strong magnetism distinguish 
this species from the following. 

Obs. Magnetic iron ore occurs in extensive beds, and also 
in disseminated crystals. It is met with in granite, gneiss, 
mica schist, clay slate, syenyte, hornblende, and chlorite 
schist ; and also sometimes in limestone. 

The beds at Arendal, and nearly all the Swedish iron ore, 
consist of massive magnetic iron. At Dannemora and the 
Taberg in Southern Sweden, and also in Lapland at 
eg and Gelivara, there are mountains composed 
of it. | 

In the U. States it constitutes extensive beds, in Ar- 
chean rocks, in Warren, Essex, Clinton, Orange, Putnam, 
Saratoga, and Herkimer Cos., N. Y.; and in Sussex and 
Warren Cos., N. J. Smaller deposits occur in the several 
New England States and Canada. Also found at Magnet 





IRON. 197 


Cove, Ark.; in Sierra Co., Cal.; with hematite in the Iron 
Mountains of Missouri. 

Masses of this ore, in a state of magnetic polarity, consti- 
tute what are called lodestones or native magnets. ‘They are 
met with in many beds of the ore: in Siberia; the Hartz ; 
the Island of Elba; at Marshall’s Island, Me.; near Provi- 
dence, R.I.; at Magnet Cove, Ark. The lodestone is 
called magnes by Pliny, from the name of the country, 
Magnesia (a province of ancient Lydia), where it was 
found ; and it hence gave the terms magnet and magnetism 
to science. 


F'ranklinite. 


Isometric. In octahedral and dodecahedral crystals ; also 
coarse granular massive. Color iron-black. Streak dark 
reddish brown. Brittle H.=5°5-6°5. G.=4°5-5-l. 
Usually feebly attracted by the magnet. 

Composition. General formula like that of magnetite, 
RRO,, but having zinc and manganese replacing part of the 
iron, as indicated in the formula (Fe, Zn, Mn) (Ho, Mn) O,. 
A common variety corresponds to Fe,O, 67°6, FeO 5:8, ZnO 
60,0 .9°7 —.100. 

B.B. with soda on charcoal a zinc coating ; a soda bead 
in the outer flame is colored green by the manganese. 

Diff. Resembles magnetic iron, but the exterior color is a 
more decided black. The streak is reddish brown, and the 
blowpipe reactions are distinctive. 

Obs. Abundant at Sterling and Hamburg, Sussex Co., 
N. J.; near Franklin Furnace, crystals sometimes 4 in. in 
diameter. Amorphous at Altenberg, near Aix-la-Chapelle. 


Jacobsite, Isometric octahedrons; Fe, Mn, MnO; magnetic ; Swe- 
den. 


Chromite.—Chromic Iron. 


Isometric. In octahedrons; cleavage none. Usually 
massive, and breaking with a rough unpolished surface. 

Color iron-black, brownish black. Streak dark brown. 
Lustre submetallic; often faint. H.=—5°5. G. = 4°32-4°6. 
In small fragments attractable by the magnet. 

Composition. General formula RRO,, as for magnetite, 
with part of the iron replaced by chromium. Analysis gives 
Iron protoxide 32, chromium sesquioxide 68 = 100 ; alumi- 
nium and magnesium also commonly present, replacing 


198 DESCRIPTIONS OF MINERALS. 


the other constituents. B.B. infusible alone; with borax 
a beautiful green bead. 

This ore usually possesses less metallic lustre than the 
other black iron ores. 

Obs. Occurs usually in serpentine rocks, in imbedded 
masses or veins. Some of the foreign localities are the 
Gulsen Mountains in Styria; the Shetland Islands; the 
department of Var in France ; Silesia ; Bohemia, ete. 

At Bare Hills, Soldier’s Delight, and Owing’s Mills, near 
Baltimore, at Cooptown in Harford Co., and north part of 
Cecil Co., Md.; in Townsend and Westfield, Vt.; at Chester 
and Blandford, Mass.; at Wood’s Mine, near Texas, Lancas- 
ter Co., and in West ‘Branford, Chester Co., Pa.; Jackson 
Co., N.C.; at Bolton and Ham, Canada East ; ‘San Luis 
Obispo, Napa, Del Norte, Sonoma (near New Idria), and 
Tuolumne Cos., Cal.; at Seattle in Wyoming. 

The compounds of chromium, which are extensively used 
as pigments, are obtained chiefly from this ore; and the 
California mines afford nearly all that is used in the U. 
States ; about 2500 tons were mined in 1882. ‘The ore is 
shipped to Baltimore, and there nearly all is made into the 
bichromate for calico-printing and other purposes, Chrome 
green and chrome yellow, for use as pigments, are also 
manufactured there. About a third of the ore used at Balti- 
more, or near 2,000,000 lbs., is imported from Scotland. 


Daubréelite. A black chromium sulphide. From meteorites. 


Limonite.—Brown Hematite. 


Usually massive; often smooth botryoidal or stalactitic, 
with a compact fibrous structure within. Also earthy. 

Color dark brown and black to ochre-yellow; streak yel- 
lowish brown to dull yellow. Lustre when black sometimes 
submetallic ; often dull and earthy; on a surface of fracture 
frequently silky. H. = 5-5'5. G. = 3°6-4, 

The following are the principal varieties : 

Brown hematite. The botryoidal, stalactitic and asso- 
ciated compact ore. 

Brown ochre, Yellow ochre. Harthy ochreous varieties 
of a brown or yellow color. 

Lrown and Yellow clay iron stone. Impure ore, hard 
and compact, of a brown or yellow color. 

Bog iron ore. A loose earthy ore of a brownish black 
color, occurring in low grounds, 


IRON. 199 


Composition. FeO,H,(= 2Fe0,+ 3H,O) = Iron sesquiox- 
ide 85°6, water 14:4= 100; or a hydrous iron sesquioxide, 
containing, when pure, about two thirds its weight of pure 
iron. B.B. blackens and becomes magnetic; with borax in 
the outer flame a yellow glass. 

Diff. Amuch softer ore than either of the two preceding, 
and peculiar in its frequent stalactitic forms, and in its af- 
fording water when heated in a glass tube. 

Obs. Occurs connected with rocks of all ages, but appears, 
as shown by the stalactitic and other forms, to have resulted 
in all cases from the decomposition of other iron-bearing 
rocks or minerals. 

An abundant ore in the United States. Extensive beds 
exist in Salisbury and Kent, Ct.; in Beekman, Fishkill, 
Dover, Amenia, N. Y.; in a similar situation in Richmond 
and West Stockbridge, Mass.; in Bennington, Monkton, 
Pittsford, Putney, and Ripton, Vt.; in Pennsylvania, the 
Carolinas, Virginia, and the region southwestward ; also in 
Missouri, Iowa, Wisconsin, etc. 

This is one of the most valuable oresof iron. The limo- 
nite of Western New England, and that along the same 
range geologically in Dutchess Co., New York, Eastern 
Pennsylvania, and beyond is remarkably free from phos- 
phorus, and hence is highly valued for its iron. Log ores 
usually contain much phosphorus, from organic sources, 
and hence the iron afforded is best fitted for castings. Li- 
monite is also pulverized and used for polishing metallic 
buttons and other articles. As yellow ochre, it is a common 
material for paint. 


Gothite (Pyrrhosiderite, Lepidokrokite). An iron hydrate, often in 
fine prismatic crystals, as well as fibrous and massive ; G. = 4°0-4°4; 
streak brownish yellow ; FeO,H.(= FeO; + H.0). 

Turgite. Resembles limonite, but gives a reddish powder, and has 
the formula FeO, H, =2FeO; + H.O; G.=414. It occurs with 
limonite at the ore beds of Salisbury, Ct., and others in the same 
range. XAanthosiderite and Limnite are other related hydrates. 

Melanosiderite. Hydrous iron sesquioxide, with 7°42 of silica; 
gelatinizes ; lustre vitreous ; fusible. ‘rom Mineral Hill, Pa. 


SuLPHATES, BORATE, TUNGSTATE, NIOBATES, TANTALATES. 


Wielanterite.—Copperas. Iron Vitriol. Green Vitriol. 


Monoclinic; in acute oblique rhombic prisms. Cleavage 
basal, perfect. Generally pulverulent or massive. 


200 DESCRIPTIONS OF MINERALS. 


Color greenish to white. Lustre vitreous. Subtranspa- 
rent totranslucent. Taste astringent and metallic. Brittle. 
Hoare: 1. iGias 183: 

Composition. FeO,S + Yaq (or FeO + SO,-+ Yaq)= Sui- 
phur trioxide 28°8, iron protoxide 25:9, water 45°3 = 100. 
B.B. becomes magnetic. Yields glass with borax. On ex- 
posure, becomes covered with a yellowish powder. 

Obs. This species is the result of the decomposition of 
pyrite, marcasite and pyrrhotite, which readily afford it if 
moistened while exposed to the atmosphere, and it is obtained 
from these sulphides for the arts (p. 191). An old mine 
near Goslar, in the Hartz, is a noted locality. The variety 
Luckite contains some manganese ; from Utah, Lucky Boy 
mine. 

Copperas is much used by dyers and tanners, on account 
of its giving a black color with tannic acid, an ingredient 
in nutgalls and many kinds of bark. For the same reason, 
it forms the basis of ordinary ink, which is essentially an 
infusion of nutgalls and copperas. It is also employed in 
the manufacture of Prussian blue. In the United States 
the amount made in 1884 was about fifteen million pounds, 
but none of it from U. 8. iron sulphides. 

Coquimbite, Copiapite, Voltaite, Raimondite, Botryogen, Fibroferrite, 
Utahite, Ihieite, Clinopheite, Clinochrocite, are names of other hydrous 
iron sulphates ; and Halotrichite is an iron-alum. Utahite is from the 
Tintic dist., Utah. 

f peeesie. Hydrous iron-potassium sulphate. Spain; Chaffee Co., 
Ol. 

Sideronatrite. ydrous iron-sodium sulphate; insoluble. Peru. 
Urusite is the same ; Caspian Sea. 

Pisanite. Iron-copper vitriol. Tuscany ; Turkey. 

Lagonite. ydrous iron borate. From the Tuscan lagoons. 


Wolframite.—Wolfram. Iron-manganese Tungstate. 


Monoclinic. Also massive. Color dark grayish black. 
Streak dark reddish brown. Lustre submetallic, shining, 
or dull. H. =5-5°5. G. = 7:1-7°5. 

Composition. (Fe,Mn)O,W (or (Fe,Mn)O+ WO,). A 
typical variety affords tungsten trioxide 76°47, iron prot- 
oxide 9°49, manganese protoxide 14°04 = 100. B.B. fuses 
easily to a magnetic globule; with aqua regia dissolved 
with the separation of yellow tungsten trioxide. Hiibnerite 
is a manganese wolframite, containing no iron; and Fer- 
berite is an iron wolframite. 


IRON. 201 


Found often with tin ores. Occurs in Cornwall; at 
Zinnwald and elsewhere. In the U. States, at Monroe and 
Trumbull, Ct.; on Camdage Farm, near Blue Hill Bay, 
Me.; near Mine La Motte, Mo.; at the Flowe Mine, N. C.; 
in Mammoth Mining district, Nev. (Hiidnerite); the same 
in Ouray Co., Col., and in Montana. 

The metal tungsten is employed to some extent in making with 
irona kind of steel harder than ordinary steel. Soluble tungstates also 


have some uses in the arts. 
feinite, Like wolframite in composition, but tetragonal. 


Colum bite. 


Orthorhombic; JA JZ over 7-i=100° 40’, TA¢-i= 
140° 20’. In rectangular prisms, more or less modified. 
Also massive. Cleavage parallel to 
the lateral faces of the prism, some- 
what distinct. 

Color iron-black, brownish black ; 
often with acharacteristic iridescence 
on a surface of fracture. Streak dark 
brown, slightly reddish. Lustre sub- 
metallic, shining. Opaque. Brittle. 
H. =5-6. G. =5°4-6'5; also 6-6'85 
when containing tantalum. 

Composition. Iron niobate, of the . 
formula FeO,Nb, (or (R,Mn)O + Nb,O,) = Niobium pen- 
toxide 79°6, iron protoxide 16°4, manganese protoxide 4°4, 
tin oxide 0°5, lead and copper oxides 01 = 100. ‘Tantalum 
often replaces part of the niobium. B.B. alone infusi- 
ble. Imparts to the borax bead the yellow color due to 
iron. 

Diff. Its dark color, submetallic lustre, and a slight iri- 
descence, together with its breaking readily into angular 
fragments, will generally distinguish this species from the 
ores it resembles. 

Obs. In granite at Bodenmais, Bavaria; in Bohemia; in 
the U. States, in granitic veins, at Middletown, Haddam, 
and Branchville, Ct.; Chesterfield, Beverly, and Northfield, 
Mass.; Acworth, N. H.; Greenfield, N. Y.; Standish, Me.; 
in granite veins in Amelia Co.. Va.; at Pike’s Peak, Col.; 
Black Hills, Dak. A crystal from Middletown originally 
weighed 14 pounds avoirdupois; a single mass occurred in 


the Black Hills weighing a ton (W. P. Blake). 





202 DESCRIPTIONS OF MINERALS. 


This mineral was first made known from American speci- 
mens by Mr. Hatchett, an English chemist, and the new 
metal it was found to contain was named by him columbium. 

Tantalite. Fe(Mn)O.Ta.2; with sometimes tin and tungsten. Allied 
to columbite; H. = 6-6°5; G. = 7-8; being distinguished by its high 
specific gravity. Finland; Sweden; near Limoges in France; 
N. Carolina; Alabama. The Northfield and Branchville columbites 
are nearly tantalite in composition, and that of the Black Hills is 
probably the same species. Mangantantalite contains more manganese 
than iron. 

Wote.—The metal named Columbium by Hatchett is the same that 
was later called Wivbiwm, without any good reason for the change of 
name. 


PHOSPHATES, ARSENATES. 
Vivianite.—Hydrous Iron Phosphate. 


Monoclinic. In modified oblique prisms, with cleavage 
in one direction highly perfect. Also radiated, reniform, 
and globular, or as coatings. 

Color deep blue to green and white. Crystals usually 
green at right angles with the vertical axis, and blue paral- 
leltoit. Streak bluish. Lustre pearly to vitreous. T'rans- 
parent to translucent; opaque on exposure. ‘Thin lamin 
flexible. H.=1°5-2. G. = 2°58-2°68. 

Composition. Fe,O,P, +8 aq (or 3FeO + P,O, + 8 aq) 
= Phosphorus pentoxide 28°3, iron protoxide 43° 0, water 
28°7 = 100. B.B. fuses easily toa magnetic elobule, color- 
ing the flame greenish blue. Affords water in a glass tube, 
and dissolves in hydrochloric acid. Changes by oxidation 
of the iron. 

Diff. The deep-blue color and the little hardness are 
decisive characteristics. The blowpipe affords eae 
tests. 

Obs. Found with iron, copper and tin ores, and some- 
times in clay, or with bog iron ore. St. Agnes in Cornwall, 
Bodenmais, and the gold-mines of Véréspatak in Transyl- 
vania, afford fine cr ystallizations. In the U. States, in 
crystals at Imlaystown, N. J.; at Allentown, in Monmouth 
Co., Mullica Hill, in Gloucester Co., N. J. Often fills the 
interior of certain fossils. Also at Harlem, N. Y.; in 
Somerset and Worcester Cos., Md.; with bog ore in Staftord 
Co., Va. Abundant at V audreuil, Canada, with limonite. 
The blue iron earth is an earthy variety, miei about 
30 p. c. of phosphoric acid. 


IRON. 203 


Ludiamite. In monoclinic crystals; clear green; hydrous phosphate 
of iron. Cornwall. Koninckite is another, from Belgium. 

Dufrenite. A hydrous phosphate of iron sesquioxide; color dull 
green; often in radiated forms. Destinegiie is related to it; Péc?te also. 

Cacorenite, In radiated silky tufts; color yellow or yellowish 
brown; H. =3-4; G. = 8°38; phosphate of iron sesquioxide ; often 
contains alumina. Differs from wavellite, which it resembles, in its 
yellower color and iron reactions. Also resembles carpholite, but 
has a deeper color, and does not give the manganese reactions. On 
limonite in Bohemia. 

Chalcosiderite and Andrewsite are other iron phosphates. 

Richellite. Supposed to be an iron-calcium fluo-phosphate; G. = 2; 
cream-yellow. Richelle, belgium. 

Strengite. Hydrous iron phosphate, related in formula to scoro- 
dite; orthorhombic; reddish. Near Giessen, Germany. 

Triphylite. An iron manganese-lithium phosphate. See p. 208. 

Pharmacosiderite, or Cube ore. In cubes; dark green to brown and 
red; lustre adamantine, not very distinct; streak greenish, brownish; 
H. =25;G@.=3. A hydrous arsenate of iron sesquioxide, contain- 
ing 43 per cent. of arsenic pentoxide. Cornwall; France; Saxony; 
Hungary. 

Scorodite. Orthorhombic; pale leek-green or liver-brown; vitreous 
to subadamantine ; subtransparent to nearly opaque; H. = 3°5-4; 
G. = 3°1-3°3; a hydrous arsenate of iron sesquioxide. Saxony; 
Carinthia; Cornwall; Brazil; and minute crystals near Edenville, 
N. Y., with arsenical pyrites. Named from the Greek skorodon, 
garlic, alluding to the odor B.B. Jron sinter is an amorphous form 
of the same. 

Arseniosiderite is another iron arsenate. 

EHmmonsite. Monoclinic?; yellowish green; G. about 5; probably 
tellurite of iron. Near Tombstone, Arizona. 


CARBONATES. 
Siderite.—Spathic Iron. Iron Carbonate. Chalybite. 


Rhombohedral; RAR=107°. Cleavage parallel to 
Fi easy. Faces often curved. Usually massive, with a 
foliated structure, somewhat curving. Some- 
times in globular concretions or implanted — Wy 
globules. / 

Color grayish white to brown; often dark “ 
brownish red. Becomes nearly black on ex- ” 
posure. Streak uncolored. Lustre pearly ‘Translucent to 
nearly opaque. H. = 3-45. G. =3:°7-3°9. 

Composition. FeO,C (or FeO + CO,)= Carbon dioxide 
37°9, iron protoxide 62°1=100. Often contains some 
manganese oxide or magnesia, and lime replacing part of 
the iron protoxide. B.B. it blackens and becomes magnetic; 





204 DESCRIPTIONS OF MINERALS. 


but alone it is infusible. Dissolves in heated hydrochloric 
acid with effervescence. ‘The iron, on exposure to the air, 
passes to the sesquioxide state, and usually to the hydrous 
iron sesquioxide (limonite), giving the siderite a brown or 
brownish yellow color. 

The ordinary crystallized or foliated variety is called 
spathic or sparry iron, because the mineral has the aspect 
of aspar. The globular concretions found in some amygda- — 
loidal rocks have been called spherosiderite because of its 
spheroidal forms. An argillaceous variety occurring in nod- 
ular forms is often called clay tron stone, and is abundant 
in coal measures. 

Diff. Cleavage as in calcite and dolomite, but specific 
gravity higher. B.B. readily becomes magnetic. 

Obs. Occurs in rocks of various ages, and often accom- 
panies other ores. Large deposits and veins exist in gneiss 
and mica schist, clay slate; also in some limestone; in: the 
Coal formation principally in the form of clay iron-stone. 
In Styria and Carinthia, abundant in gneiss ; in the Hartz, 
in graywacke. Cornwall, Alstonmoor, and Devonshire are 
English localities. 

In a vein in gneiss at Roxbury, Ct.; occurs also at Plym- 
outh, Vt.; Sterling, Mass.; in Antwerp, Jefferson Co., 
and Hermon, St. Lawrence Co., N. Y.; in large masses in 
and beneath the limonite of Salisbury, Ct.; Amenia, N. Y.; 
W. Stockbridge, Mass.; being, it is supposed, part of the un- 
derlying limestone; abundant in a bed of limestone south of 
Hudson, N. Y., and now worked. Clay iron-stone is abun- 
dant in the coal regions of Pennsylvania and other coal- 
bearing States. 

This ore is employed extensively for the manufacture of 
iron and steel. 

Mesitite is an iron-magnesium carbonate. 

Ankerite is like mesitite, but contains in addition a large percentage 
of calcium. Both make parts of many dolomitic limestones, and are 
the occasion of their becoming rusty and decomposed, producing 


limonite. 
Humboldtine. A hydrous iron oxalate. 


General Remarks.—The metal iron has been known from the most . 
remote historical period, but was little used until the last centuries be- 
fore the Christian era. Bronze, an alloy of copper and tin, was the 
almost universal substitute, for cutting instruments as well as weapons 
of war, among the ancient Egyptians and earlier Greeks ; and even 
among the Romans (as proved by the relics from Pompeii), and also 


IRON. 205 


throughout Europe, it continued long to be extensively employed for 
these purposes, 

The Chalybes, bordering on the Biack Sea, were workers in iron and 
steel at an early period ; and near the year 500 B.c., this metal was 
introduced from that region into Greece, so as to become common for 
weapons of war. From this source we have the expression chalybeate 
applied to certain substances or waters containing iron, 

‘The iron-mines of Spain have also been known from a remote epoch, 
and it is supposed that they have been worked ‘‘at least ever since 
the times of the later Jewish kings ; first by the Tyrians, next by the 
Carthaginians, then by the Romans, and lastly by the natives of the 
country.” ‘These mines are mostly contained in the present provinces 
of New Castile and Aragon. Elba was another region of ancient 
works, ‘‘inexhaustible in its iron,” as Pliny states, who enters some- 
what fully into the modes of manufacture. The mines are said to 
have yielded iron since the time of Alexander of Macedon. The ore 
beds of Styria, in Lower Austria, were also a source of iron to the 
Romans. 

The ores from which the iron of commerce is obtained are the sider- 
ite (spathic iron), magnetite (magnetic iron), hematite (specular iron), 
limonite (‘‘ brown hematite”), and bog iron ore. In England, the prin- 
cipal ore used is an argillaceous carbonate of iron, called often clay 
iron stone, found in nodules and layers in the coal measures. It con- 
sists of carbonate of iron, with some clay, and externally has an earthy, 
stony look, with little indication of the iron it contains except in its 
weight. It yields from 20 to 35 per cent. of cast iron. The coal basin 
of South Wales, and the counties of Stafford, Salop, York, and Derby, 
yield by far the greater part of the English iron. Brown hematite is 
also extensively worked. In Sweden and Norway, at the famous 
works of Dannemora and Arendal, the ore is the magnetic iron ore, 
and is nearly free from impurities as it is quarried out. It yields 50 to 
60 per cent. of iron. The same ore is worked in Russia, where it 
abounds in the Urals. The Elba ore is the specular iron or hematite. 
In Germany, Styria, and Carinthia, extensive beds of spathic iron are 
worked. The bog ore is largely reduced in Prussia. 

In the United States all these different ores are worked. The local- 
ities are already mentioned. The magnetic ore is reduced in New 
England, New York, Northern New Jersey, and sparingly in Pennsyl- 
vania, and other States. Limonite, or brown hematite, is largely 
worked along Western New England and Eastern New York, in Penn- 
sylvania, and many States South and West. The earthy argillaceous 
carbonate like that of England, and the hydrate, are found with the 
coal deposits, and are a source of much iron. 

The number of tons (2240 Ibs.) of iron manufactured in the world 
in the year 1882 was about 21,000,000, of which Great Britain pro- 
duced 8,500,000 tons, U. States 4,623,000 tons, Germany 3,171,000 tons, 
France 2,033,000 tons, Belgium 717,000 tons, Austria with Hungary 
525,000 tons, Russia 450,000 tons, Sweden 440,000 tons, other coun- 
tries 210,000. In 1860 the number of tons produced in the U. States 
was less than 900,000; in 1883, about 4,600,000; in 1884, 4,100,000. 


206 DESCRIPTIONS OF MINERALS. 


MANGANESE. 


The common ores of manganese are the oxides, the car- 
bonate, and the silicates. ‘There are also sulphides, an ar- 
senide, and phosphates. Specific gravity not over 5:2. 


[SULPHIDES AND ARSENIDES. 


Alabandite or Manganblende. A manganese sulphide, Mn§S; iron 
black ; streak green ; lustre submetallic ; H. = 3°5-4; G. = 3:°9-4:0; 
crystals, cubes, and regular octahedrons. Gold-mines of Nagyag, 
Transylvania ; Morococha, Peru; Summit Co., Col. 

Hauertte. A sulphide, MnS?; reddish brown, brownish black, re- 
sembling blende; H.=4; G.=3°46. Hungary. 

Kanette. Manganese arsenide ; grayish white ; metallic; B.B. gives 
off alliaceous fumes ; G. = 5°55. Saxony. 

Manganostibiite contains both arsenic and antimony. Sweden. 


OXIDES. 
Manganosite. 


Isometric crystals ; cleavage cubic. Emerald green, but 
brown after exposure. Lustre vitreous. H.=5-6. G.= 
5.18. 

Composition. MnO, or manganese protoxide. From 
Longban and Nordmark, Sweden. 


Pyrolusite.—Manganese Dioxide. Black Oxide of Manganese. 


Orthorhombic ; 7A J=93° 40’. In small rectangular 
prisms, more or less modified. Some- 
LL gates times fibrous and radiated or diver- 
a gent. Often massive and in reniform 
coatings. Color iron-black. Streak 
black, non-metallic. H. = 2-2°5. 
G. = 4°8. 
Composition. MnO, = Manganese 
ous 63°2, oxygen 36°8 = 100. With a mi- 
nute portion, borax bead deep amethys- 
tine while hot, red-brown on cooling. Yields no water in 
a matrass. 
Diff. Differs from iron ores by the violet glass with 
borax. 
Obs. Extensively worked in Thuringia, Moravia, and 
Prussia. Common in Devonshire and Somersetshire in 


MANGANESE. 207 


England, and in Aberdeenshire. In the United States, 
associated with the following species at Bennington, Bran- 
don, Monkton, Chittenden, and Irasburg, Vt.; occurs also 
at Conway, Plainfield, and Richmond, Mass.; in Salisbury 
and Kent, Ct.; the Etowah region, Barton Co., Ga.; Au- 
gusta, Nelson, Rockingham, and Campbell Cos., Va.; the 
Crimora mine in Augusta Co., one of the best in the United 
States; on Red Island, in the Bay of San Francisco; at 
Pictou and Walton, N. Scotia; near Bathurst, in N. 
Brunswick. 

Named pyrolusite from the Greek pwr, fire, and luo, to 
wash, alluding to its property of discharging the brown and 
green tints of glass. 


Hausmannite. A manganese oxide, 2MnO-+ MnOz, yielding 72°1 
per cent. of manganese, when pure; brownish black; submetallic; 
massive and in tetragonal octahedrons; H. = 5-5:5; G.=4°7. Thu- 
ringia ; Alsatia. 

Heterolite. A zinc-hausmannite. Sterling Hill, N. J. 

Braunite. A manganese oxide containing 69 per cent. of manganese 
when pure; color and streak dark brownish black; lustre submetallic; 
tetragonal octahedrons and massive; H. = 6-65; G.=4°8. Pied- 
mont; Thuringia. 

Manganite. A hydrous manganese sesquioxide; massive and in 
rhombic prisms; steel-black to iron-black; H. = 4-45; G@. = 4°3-4°4. 
The Hartz; Bohemia; Saxony; Aberdeenshire; at several points in 
New Brunswick and Nova Scotia. 

Crednerite. Cupreous manganese oxide. 


Psilomelane. 


Massive and botryoidal. Color black or greenish black. 
Streak reddish or brownish black, shining, H. = 5-6. 
G. = 4-4°4, 

Composition. Essentially manganese dioxide with a little 
water, and some baryta or potassa; of varying constitution. 
B.B. like pyrolusite, except that it affords water. Lithio- 
phorite is a lithia-bearing variety. 

Obs. An abundant ore, associated usually with pyrolusite; 
the two often in alternating layers; has been considered 
impure pyrolusite. Named from the Greek psilos, smooth 
or naked, and melas, black. 

Pyrochroite. ydrous manganese protoxide, of white color; 
MnO.H2. Sweden. - 

Pelagite. The brownish black concretionary manganese nodules 


found in many regions over the bottom of the ocean; affords, accurd- 
ing to an analysis, about 40 per cent. of MnOz, 27 FeO;, 13 of water 


208 DESCRIPTIONS OF MINERALS. 


lost at a red heat, along with 14 per cent. of silica and 4 of alumina; 
24°5 per cent. of water lost below 100° C. Probably a mixture. 

Chalcophanite. A hydrous manganese zinc oxide in rhombohedral 
crystals and stalactites. Sterling Hill, Sussex Co., N. J. 


Wad.—Bog Manganese. 


Massive, reniform, earthy; in coatings and dendritic 
delineations. Color and streak black or brownish black. 
Lustre dull, earthy. H.=1-6. G.=3-4. Soils the 
fingers. 

Composition. Manganese dioxide, in varying proportions, 
from 30 to 70 per cent., mechanically mixed with more or 
less of iron sesquioxide, and 10 to 25 per cent. of water. 
Often several p. c. of cobalt oxide present (var. AOE) : 
and sometimes 4-18 p. c. of copper oxide (Lampadite). It 
is formed in low places from the decomposition of minerals 
containing manganese. Gives off much water when heated, 
and affords a violet glass with borax. 

Obs. Wad occurs in Columbia and Dutchess counties, 
N. Y.; at Blue Hill Bay, Dover, Me.; at Nelson, Gilman- 
ton, and Grafton, N. H.; and in many other parts of the 
country. 

__ It may be employed like the preceding in bleaching, but 
is too impure to afford good oxygen. It may also be used 
for umber paint. 


SULPHATES. 
Mallardite. 


Fine, fibrous. Color white. Lasily soluble. 

Composition. Hydrous manganese sulphate, MnO,S + 
7 aq (or MnO + SO, + 7 aq). 

Obs. From the Silver Mine Lucky Boy, Butterfield 
Cafion, Utah. 


Semikite. Another hydrous sulphate with less water. Transyl- 
vania. 

Tlesite. Hydrous manganese zinc-iron sulphate; white; soluble. 
Hall Valley, Col. 


PHOSPHATES, ARSENATES, 
Triphylite. 


Orthorhombic. In rhombic crystals, massive. Color 
greenish gray to bluish gray, but often brownish black ex- 


MANGANESE. 209 


ternally from the oxidation of the manganese present. 
Streak grayish white. Lustre subresinous.s H.=5. G. = 
354-3 '6. 

Composition. A hydrous phosphate of iron, manganese 
and lithium, ({1i,3R),0,P,, in which R stands for Fe and 
Mn. A Bodenmais specimen afforded Phosphorus pen- 
toxide 44°19, iron protoxide 38°21, manganese protoxide 
5°63, magnesia 2°39, lime 0°76, lithia 7°69, soda 0°74, pot- 
ash 0°04, silica 0°40 = 100°05. 3B.B. fuses very easily, 
coloring the flame red, in streaks, with a pale bluish green 
on the exterior of the flame. Soluble in hydrochloric acid. 

Obs. Found at Rabenstein in Bavaria; in Finland; at 
Norwich, Mass.; Grafton, N. H. 


Lithiophilite. A salmon-colored manganese-lithium phosphate, al- 
lied in composition to triphylite, but containing very little iron. 
From Branchville, Ct. 

Fairfieldite. Hydrous manganese-calcium phosphate ; triclinic; 
white, yellowish; B.B. fuses with difficulty. From Branchville, Ct.; 
also Bavaria. 

Leucomanganite. Snow-white, but contains manganese, iron, alka- 
lies, and water. Rabenstein. Probably fairfieldite. 


Triplite. 


Orthorhombic; 7A 7 = 120° 54’. Usually massive; cleav- 
age in three directions. Color blackish brown. Streak 
yellowish gray. Lustre resinous. Nearly or quite opaque. 
H.=5-5°5. G, =3°43°8. 

Composition. (Mn,Fe),0O,P,+ RF, (or 3(Mn,Fe)O + 
P.O, + RF,), affording about 30 per cent. of manganese 
protoxide, 8 of fluorine. Fuses easily to a black magnetic 
globule. B.B. imparts a violet color to the hot borax bead. 
Dissolves in hydrochloric acid. 

Obs. From Limoges in France; Washington, Ct.; Ster- 
ling, Mass. 

Heterosite, Alluaudite, Pseudotriplite. Regarded as results of altera- 
tion, either of triphyline or of triplite. 

Talktriplite is a triplite containing calcium and magnesium. 

Triploidite. A manganese-iron phosphate, like triplite, but having 
the fluorine replaced by the elements of water. From Branchville, Ct. 

Dickinsonite. Oil-green to olive-green ; manganese-iron-calcium 
phosphate. From Branchville, Ct. 

Reddingite. Rose-pink; hydrous manganese-iron phosphate. Mns 
O;:P2 + 8aq., isomorphous with scorodite. Branchville, Ct. 

Hureaulite. Rose-colored to brownish orange; hydrous manganese- 
iron phosphate. Hureaux, France. 


14 


210 DESCRIPTIONS OF MINERALS. 


Fillowite. Manganese-iron-sodium phosphate; monoclinic; yellow, 
brown. From Branchville, Ct. 

ARSENATES OF MANGANESE. Allaktite, Diadelphite, Hemafibrite, 
Synadelphite, Polyarsenite, Surkinite, are names of arsenates. From 

weden. 


CARBONATES. 
Rhodochrosite.—Manganese Carbonate. 


Rhombohedral; RA R= 106° 51’; like calcite in having 
three easy cleavages, and in lustre. Color rose-red. H.= 
3°5-4'°5. G. = 3°4-3°7. 

Composition. MnO,C (or MnO + CO,) = Carbonic acid 
38°6, manganese protoxide 61°4=100. Part of the man- 
ganese often replaced by calcium, magnesium, or iron. 

Obs. From Saxony, Transylvania, the Hartz, Ireland ; 
Mine Hill, N. J.; Branchville, Ct.; Austin, Nev.; Alice 
Mine, Butte City, Montana; Summit Co., Col.; Placentia 
Bay, Newfoundland. 


Rhodonite, Kentrolite, Helvite. Manganese silicates. See p. 268. 


General Remarks.—The most productive localities of manganese ore 
in the United States are those of Augusta Co., Va., and Barton Co , 
Ga. The former produced, in 1885, 18,745 tons; the latter 2580; 
Arkansas about 1500, and other States about 500 tons. It is imported 
from Nova Scotia and Spain. 

Manganese is never employed in the arts in the pure state. In the 
condition of ore, especially pyrolusite, it is largely employed in bleach- 
ing. The importance of the ore for this purpose depends on the 
oxygen it contains, and the facility with which this gas is given up, 
When this ore is treated with hydrochloric acid, the chlorine of the 
acid is given off ; and by receiving this gas in slaked lime ‘‘ bleach- 
ing powder” is made, a mixture of calcium chloride with calcium 
hypochlorite. The ore easily gives off its oxygen when highly heated, 
and its use in discharging the green and brown color of glass (due to 
iron) depends on this. The binoxide of manganese, when pure, 
affords 18 parts by weight of chlorine to 22 parts of the oxide; or 234 
cubic inches of gas from 22 grains of the oxide. The best ore should 
give about three-fourths its weight of chlorine, or about 7000 cubic 
inches to the pound avoirdupois. 

Tron ores containing some manganese are used for making spiegel- 
eisen, a hard highly crystallized pig-iron, containing 10 to 15 p. ce. of 
manganese with a large amount of carbon. This spiegeleisen is com- 
monly used in the Bessemer process for making steel. Manganese is 
also employed to give a violet color to glass. The sulphate and the 
chloride of manganese are used in calico printing. The sulphate 
gives a chocolate or bronze color. Manganese borate has been used 
to give the drying quality to varnishes, 


ALUMINIUM. 211 


ALUMINIUM. 


The aluminium compounds among minerals include a 
sesquioxide AlO,, hydrated oxides, fluorides, sulphates, 
phosphates, and numerous silicates. ‘There are no sul- 
phides or arsenides, and no carbonate, with a single excep- 
tion. 

The silicates are described in the following section. Many 
infusible aluminium compounds may be distinguished by 
means of a blowpipe experiment, as explained on page 98. 

The metal aluminium is obtained by different methods 
from alumina, and the fluoride (cryolite); and recently, at 
Cleveland, from corundum easily by electric heating; reduc- 
ing the price to five dollars a pound, or a third of the previous 
cost (Am. J. Sci. xxx., 308, 1885). It is highly useful 
in alloys with copper as aluminium bronze, and also with 
iron and other metals. 


OXIDES. 


Corundum. 


Rhombohedral ; RA R= 86° 4’. Cleavage sometimes 
perfect parallel to O, and sometimes parallel to R. Usual 
in six-sided prisms, often with uneven sur- 
faces, and veryirregular. Also granular mas- 
sive. Colors: blue, and grayish blue most 
common; gray, red, yellow, brown, and nearly 
black; often bright. When polished on the 
surface O, an internal star of six rays some- 
times distinct. Transparent to translucent. 
H. = 9, or next below the diamond. Ex- 
ceedingly tough when compact. G. = 4 when 
pure; 3°94-4°16. 

Composition. AlO,= Oxygen 46'8, aluminium 53°2 = 100; 
pure alumina. B.B. unaltered both alone and with soda. 
In fine powder with cobalt nitrate and ignited, becomes 
blue. 

VARIETIES. The name sapphire is usually restricted, in 
common language, to clear crystals of bright colors, used as 
gems; while dull, dingy-colored crystals and masses are 
called corundum, and the granular variety of bluish gray 
and blackish colors containing much disseminated magnetite 
(whence its dark color) is called emery. 





212 DESCRIPTIONS OF MINERALS. 


Blue isthe true sapphire color. It is called oriental ruby, 
when red; oriental topaz, when yellow; oriental emerald, 
when green; oriental amethyst, when violet; and adaman- 
tine spar, when hair-brown. Crystals with a radiate cha- 
toyant interior are very often beautiful, and are called 
asteria, or asteriated sapphire. 

Diff. Distinguished readily by its great hardness. 

Obs. The sapphire is often found loose in the soil. Meta- 
morphic rocks, especially gneissoid mica schist, and granu- 
lar limestone, appear to be its usual matrix. It is met with 
in several localities in the United States; blue at Newton, 
N. J., crystals sometimes several inches long, also at Frank- 
lin and Sparta; bluish and pink crystals at Warwick, and 
white, blue, and reddish at Amity, N. Y.; grayish, in large 
crystals, in Delaware and Chester Cos., Pa.; pale blue in 
bowlders at West Farms and Litchfield, Ct. Abundant at 
Corundum Hill, Macon Co., N. C., where crystals are nu- 
merous, and some fit for jewelry, and where one has been 
obtained weighing 312 pounds, having a reddish color out- 
side and a bluish-gray within; also in Jackson, Burke, 
Heywood, Madison, and Clay, and other Cos.; Laurens 
Dist., S. C.; Tallapoosa Co., Ala.; alsoin Fannin Co., Ga.; 
Los Angeles Co., Cal.; near Helena, Montana, affording 
some good gems; Santa Fé, N. Mexico; Arizona; Colorado; 
emery, formerly mined, at Chester, Mass. 

The principal foreign localities are as follows: blue, from 
Ceylon; the finest red from the Capelan Mountains in the 
kingdom of Ava, and smaller crystals from Saxony, Bohemia, 
and Auvergne; corundum, from the Carnatic, on the Mala- 
bar coast, and elsewhere in the East Indies; adamantine 
spar, from the Malabar coast; emery, in large bowlders, from 
near Smyrna, and also at Naxos and several of the Grecian 
islands. 

The name sapphire is from the Greek word sapphevros, the 
name of a blue gem. It is doubted whether it included the 
sapphire of the present day. 

Next to the diamond, the sapphire in some of its varieties 
is the most costly of gems. The red sapphire is much more 
highly esteemed than those of other colors; a crystal of one, 
two, or three carats has the value of a diamond of the same 
size. They seldom exceed half an inch in their dimensions. 
Two splendid red crystals, as long as the little finger and 
about an inch in diameter, are said to be in the possession 


ALUMINIUM. 213 


of the king of Arracan. The largest oriental ruby known 
was brought from China to Prince Gargarin, governor of 
Siberia; it afterwards came into the possession of Prince 
Menzikoff, and constitutes now a jewel in the imperial 
crown of Russia, Blue sapphires occur of much larger 
size. According to Allan, Sir Abram Hume possessed a 
crystal which was three inches long. One of 9°51 carats is 
stated to have been found in Ava. 

Corundum and emery are crushed to a powder of differ- 
ent degrees of fineness, and make the abrading and _ polish- 
ing material called in the shops emery. The iron oxide of 
true emery diminishes its hardness, and consequently its 
abrasive power; pulverized corundum is more valuable and 
efficient in abrasion. 


Diaspore. Aluminium hydrate, A10.H) (orA10;H.O) = Water 14 9, 
alumina 85°1 = 100; crystals usually thin plates; also acicular; whitish, 
grayish, pinkish, etc.; brittle; translucent; H. 6°5-7; G. 3°5. The 
Urals; Schemnitz; Chester, Mass. ; - Unionville, Chester Co., Pa., some 
cryst. 13 in. long; Culsagee mine, A ee OF Usually found with corun- 


um. 

Gibdsite (Hydrargillite). Aluminium hydrate; AlO,H. =Water 34°5, 
alumina 65°5 =100. In hexagonal crystals, sometimes transparent; 
commonly in whitish stalactitic and mammillary forms, with smooth 
surface, looking like chalcedony; H.= 2°5-3°5; G.= 2°3-2°4. Near 
Slatoust in the Ur al; Asia Minor; on corundum at Unionville, Pa.; at 
Richmond, Mass., stalactitic; in Dutchess and Orange Cos., N. Y. 
Zirlite is similar. 

Hydrotaleite (Vitknerite, Houghite). Soft pearly; contains alumina, 
magnesia, and water. A result of the alteration of spinel crystals. 
Near Slatoust; Snarum, Norway; Oxbow, Rossie, St. Lawrence Co., 
N. Y. (var. Houghite). 

Beauxite. Alauminium-iron hydrate; in concretionary forms and 
grains. Beaux, France, etc. 


Spinel. 


Isometric. In octahedrons, more or less modified. Fig- 
ure 3 represents a twin crystal, Occurs only in crystals; 
cleavage octahedral, but difficult. 

Color red, passing into blue, green, yellow, brown, and 
black. The rod shades often transparent and bright: the 
dark shades usually opaque. Lustre vitreous. H. = 8. 
G. =35-4'1. 

Composition. MgAlO, (or MgO +410,) = Alumina 72, 
magnesia 28=100. The aluminium is sometimes re- 
placed in part by iron, and the magnesium often in part by 


214 DESCRIPTIONS OF MINERALS. 


iron, calclum, manganese, and zinc. Infusible; insoluble 
in acids. 

VARIETIES. The scarlet or bright red crystals, spinel 
ruby; rose-red, balas-ruby; orange-red, rubicelle; violet, 
almandine ruby; green, chloro-spinel; black, pleonaste. 


iL 2. 3. 





Pleonaste contains sometimes 8 to 20 per cent. of oxide of 
iron. Picotite contains iron with 7 p. c. of chromium 
oxide; G. = 4°08. 

Diff. The form of the crystals and their hardness dis- 
tinguish the species. Garnet is fusible. Magnetite is at- 
tracted by the magnet. Zircon has a higher specific gravity. 
The red crystals often resemble the true ruby (red corun- 
dum), but the latter are never in octahedrons. 

Obs. Occurs in granular limestone; also in gneiss and 
volcanic rocks, At numerous places in the adjoining coun- 
ties of Sussex, N. J., and Orange Co., N. Y., of various 
colors from red to brown and black; especially at Vernon, 
Franklin, Newton, and Hamburg, in the former, and in 
Warwick, Amity, Monroe, Norwich, Cornwall, and Hden- 
ville in the latter. One octahedron, found at Amity by 
Dr. Heron, weighed 49 pounds. ‘The limestone quarries 
of Bolton, Boxborough, Chelmsford, and Littleton, Mass., 
afford a few crystals; also San Luis Obispo, Cal.; bluish, 
at Wakefield, Canada. 

Crystals of spinel have occasionally undergone a change 
to the steatite-like mineral hydrotalcite (see p. 213). 

Uses. ‘The fine colored spinels are much used as gems. 
The red is the common ruby of jewelry, the ovtental rubies 
being sapphire. 


Gahnite. A spinel in which zinc takes the place of part or all of 
the magnesium; when all, it is called Awtomolite ; dark green or 
greenish black ; H. = 7°5-8; G@. = 4-4°6; fused with sufficient soda, 
B.B. on coal, a white coat of zinc oxide, which is yellow when hot ; 
B.B. infusible. Franklin, N. J.; Rowe, Mass., in a vein of pyrite; 


ALUMINIUM. 215 


Mitchell Co., Deak mine, N. C.; Canton mine, Ga.; Colorado ; New 
Mexico ; Sweden, near Fahlun, in talcose slate. 

Dysluite. A gahnite containing manganese; yellowish or grayish 
brown; H. = 7'5-8; = 4°55 ; composition, Alumina 380°5, zinc 
oxide 16: 8, iron sesquioxide 41° 9, manganese protoxide 76, silica 3, 
water 0°4. Sterling, N. J., with franklinite and troostite. 

Kreittonite. A zinc-iron gahnite; G. = 4°48-4'89., 

Hereynite. A spinel affording on analysis alumina and iron pro- 
toxide, with only 2°9 per cent. of magnesia ; G. = 3°9-3°95. 


Chrysoberyl. 


Orthorhombic; JA 7=129° 38’. Also in compound 
crystals, as in Fig. 2. Crystals sometimes thick; often 
tabular. 

Color bright green, from light to emerald-green and 
brown; rarely raspberry- or columbine-red by transmitted 
light. "Streak uncolored. Lustre vitreous. Transparent 
to translucent. H.=8°5. G. =3-7-3°86. 

Composition. BeAlO, (or BeQAlO,) = Alumina 80:2, 
glucina 19°8=100. B. B. infusible and unaltered. 

Alexandrite, from the Urals, is colored emerald-green 
by chrome; bears the same relation to ordinary chryso- 
beryl as emerald to beryl. Fig. 2 is of this variety. 

Diff. Near beryl, but distinct in not being regularly hex- 
agonal in crystallization. 

Obs. Chrysoberyl occurs in the United States in granite 
at Haddam, Ct. (loc. not accessible); Greenfield, near 
Saratoga, N. Y.; Stow (one crystal 3x5x1 inches), 
Canton, Peru, Stoneham, Norway, Maine. 





Named from the Greek chrysos, golden, beryllos, beryl. 

The crystals are seldom sufficiently pellucid and clear 
from flaws to be valued in jewelry; but when of fine qual- 
ity, it forms a beautiful gem, and is often opalescent. 


216 DESCRIPTIONS OF MINERALS. 


FLUORIDES OF ALUMINIUM. 
Cryolite.—Aluminium-Sodium Fluoride. Ice Stone. 


Monoclinic ; JA J = 883°-88°. Rectangular cleavages. 
Usually massive; white. Translucent. G. = 2°9-3°1. 

Composition. 38Na¥ + AlF, = Aluminium 13:0, sodium 
32°8, fluorine 54°2 = 100. Fusible in the flame of a candle, 
and thus easily distinguished. 

Obs. From Greenland ; sparingly, Pike’s Peak region, 
at the N. E. base of St. Peter’s Dome. Used in making 
soda, porcelain-like glass, and the metal aluminium. 
Another cryolite-like species, //pasolite, occurs at Pike’s 
Peak, in which the sodium is largely replaced by potassium. 


Pachnolite. Monoclinic; IA [= 81° 24’; white, yellowish; like 
cryolite in composition except that half the ‘sodium is replaced by 
calcium, and water is present ; formed by the alteration of cryolite. 
Greenland; Pike’s Peak, Col. 

Thomsenolite. Like pachnolite in composition; monoclinic; J A I 
near 90°; cleavage basal, very perfect; Greenland; Pike’s Peak. 

Gearksuktite. Earthy, kaolin-like; hydrous, like the last, but con- 
taining calcium with no sodium. Greenland; Pike’s Peak. Hvigto- 
kite is probably the same. 

Arksuktite, Chiolite, Chodneffite are related species, the latter two 
from Siberia. 

Ralstonite. In minute cubo-octahedrons; a hydrous sodium- 
aluminium fluoride. Occurs in Greenland cryolite : probably with 
pachnolite of Pike’s Peak. 

Fluellite, In minute white rhombic octahedrons; contains alumin- 
ium and fluorine. Cornwall. 

Prosopite. Monoclinic; white or grayish; a hydrous aluminium- 
calcium fluoride. Altenberg:; cryolite locality of Pike’s Peak. 

Chioraluminite. A hydrous aluminium chloride. Vesuvius. 


SULPHATES, BORATES. 
Alunogen.—Hydrous Aluminium Sulphate. 


In silky efflorescences and crusts of a white color, hay- 
ing a taste likecommonalum. H.=1°5-2. G.=1° 6-1°8. 

Composition. AlO,.S, + 18aq. (or Al1O, + 380, + 18aq.) 
= Sulphur trioxide 36°0, ate 15°4, water 48°6 = 100. 

Obs. Common as an efflorescence in solfataras of volcanic 
regions, and also often occurring in shales of coal regions 
and other rocks containing pyrite; the oxidation of the 
iron sulphide affords sulphuric acid, which acid combines 
with the alumina of the shale. 


ALUMINIUM. 217 


Alums, Frequently the sulphuric acid resulting from the oxidation 
of a sulphide, or in some other way, combines also with the iron, 
magnesia or potash or soda of the shale or other rock, as well as the 
alumina, and so makes other kinds of aluminium sulphate, 

Combining thus with potash, it produces common alum called Kali- 
nite or potash alum, whose formula is K,AJ;0.,8, + 18aq.; with am- 
monia, it forms an ammonia-alum, named Tschermigite ; with iron, 
iron-alum, called Halotrichite ; with soda, soda-alum, Mendozite ; 
with magnesia, magnesia-alum, Pickeringite ; with manganese, man- 
ganese alum, Apjohnite and Bosjemanite. The formulas of these 
alums are alike in atomic proportions, excepting in the amount of 
water, which varies from 18aq. to 24aq. 

Sonomaite. From the Geyser region of Sonoma Co., Cal., is near 
pickeringite. Plagiocitrite is soluble aluminium-sodium-potassium- 
iron sulphate. JLeigite is aluminium-potassium sulphate, containing 
half the water of pickeringite. Dumreicherite is a magnesian alum 
of peculiar composition. Déietrichite is near the alums. 

Shale containing alunogen or any of the alums is often called alum 
shale. Rocks, whether shales or of other kinds, are often quarried 
and lixiviated for the alum they contain or will afford. The rock is 
first slowly heated after piling it in heaps, in order to decompose the 
remaining pyrites and transfer the sulphuric acid of any iron sulphate 
to the alumina and thus produce the largest amount possible of alu- 
minium sulphate. It is next lixiviated in stone cisterns. The lye con- 
taining this sulphate is afterwards concentrated by evaporation, and 
then the requisite proportion of potassium in the form of the sulphate 
or chloride is added to the hot solution. On cooling, the alum crys- 
tallizes out, and is then washed and recrystallized. The mother 
liquor Jeft after the precipitation is revaporated to obtain the remain- 
ing alum held in solution. This process is carried on extensively in 
Germany, France, at Whitby in Yorkshire, Hurlett and Campsie, 
near Glasgow, in Scotland. Cape Sable in Maryland affords large 
quantities of alum annually. The slates of coal beds are often used 
to advantage in this manufacture, owing to the decomposing pyrites 
present. At Whitby, 130 tons of calcined schist give one ton of alum. 
In France, ammoniacal salts are used instead of potash, and an am- 
monia alum is formed, 


Alunite.—Alum Stone, 


Rhombohedral, with perfect basal cleavage. Also mas- 
sive. Color white, grayish, or reddish. Lustre of crystals 
vitreous, or a little pearly on the basal plane, ‘Transparent 
to translucent, H.=4. G. = 2°58-2°7%5. 

Composition. K,A10,,8,-+6aq. (or K,OSO, + 3Al0, 
SO, + 6aq.) = Sulphur trioxide 38°5, alumina 37:1, 
potash 11-4, water 13°0 = 100. B.B, decrepitates, infusi- 
ble; reaction for sulphur. 

Diff. Distinguished by its infusibility, and its complete 
solubility in sulphuric acid without forming a jelly. 


218 DESCRIPTIONS OF MINERALS. 


Obs. Found in rocks of volcanic origin at Tolfa, near 
Rome; and also at Beregh and elsewhere in Hungary. 

When calcined, the sulphates become soluble, and the 
alum is dissolved out. On evaporation the alum crystallizes 
from the fluid in cubic crystals. This is called Roman 
alum, and is highly valued by dyers, because, although the 
crystals are colored red by iron oxide, no iron is chemically 
combined with the salt, as is usual in common alum. 


Aluminite (Websterite). Another hydrous-aluminium sulphate, in 
compact reniform masses, and tasteless. From New Haven, in Sussex; 
Epernay, in France; and Halle, in Prussia. Werthemanite is a related 
mineral containing less water, from Chili; and Picrallwmogen an- 
other, containing about 8 p. c. of magnesia. 

: Jeremeepite. Aluminium borate; in hexagonal crystals, W. Si- 
eria. 


PHOSPHATES. 
Amblygonite.—Lithium-Aluminium Phosphate. 


Triclinic, with cleavages unequal in two directions, in- 
clined to one another 1043°. Lustre vitreous to pearly and 
greasy. Color pale mountain-green or sea-green to white. 
Translucent to subtransparent. H.=6. G. = 3-8°11. 

Composition. A lithium-aluminium phosphate, AlO,P,+ 
(LiNa),(FOH), (or AlO, + P,O,+ [Li,Na,| [FOH]). B.B. 
fuses very easily with intumescence, coloring the flame yel- 
lowish red to rich carmine-red, owing to the lithia present, 
with traces of green owing to the phosphoric acid; reaction 
also for fluorine. 

Obs. Occurs in Saxony and Norway; at Montebras 
(Montebrasite), France ; Hebron and Mount Mica (Hebdron- 
ite) in Maine; Branchville, Ct. 


Durangite. Anhydrous aluminium arsenate, containing alumin- 
ium, sodium, iron, and some manganese, with over 7 per cent. of 
fluorine; monoclinic; orange-red; G.= 3°9-4:1. Barranca tin-mine, 
Durango, Mexico, with cassiterite or tin ore. 


Lazulite. 


Monoclinic. Incrystals; alsomassive. Color azure-blue. 
H.= 5-6. G.= 3°057. 

Composition. RA1O,P,-+-aq= Phosphorus pentoxide 46:8, 
alumina 34°0, magnesia 13°2, water 6°0=100. B.B. in the 
closed tube whitens, yields water; with cobalt solution the 
color is restored; in the forceps whitens, swells, falls to 
pieces without fusion, coloring the flame bluish green. 


ALUMINIUM. 219 


Obs. From Salzburg, Styria; Wermland, Sweden; Crowder 
Mount, Lincoln Oo., N. C.; Graves Mountain, Lincoln Co., 
Ga.; Keewatin Dist., Canada. 


Variscite (Peganite, Callainite). A hydrous aluminium phosphate; 
color light green, of various shades, to deep emerald-green. From 
Montgomery Co., Ark.; Colorado; Messbach, in Saxon Voigtland. 
Fischerite is a related mineral. 

Hvansite. Hydrous aluminium phosphate; looks like allophane. 
Hungary. 

Goyazite. Hydrous aluminium-calcium phosphate; yellowish-white 
Minas Geraes, Brazil. 


Turquois. 


Massive, reniform, without cleavage. Color bluish green. 
Lustre somewhat waxy. H.=6. G.=2-°6-2°8. 

Composition. Phosphorus pentoxide 22°6, alumina 46:9, 
water 20°5=100. B.B. infusible, but becomes brown; colors 
the flame green. Soluble in hydrochloric acid; moistened 
with the acid, gives a momentary bluish green color to the 
flame, owing to the copper present. 

Diff. Distinguished from bluish green feldspar, which it 
resembles, by its infusibility and the reactions for phos- 
phorus. 

Ods. Found in a mountainous district in Persia, not far 
from Nichabour; N. Mexico, in Los Cerillos, at Mt. Chal- 
chuitl, 22 m. from Santa Fé; in Turquois Mtn., Arizona; in 
S. Nevada, 5 m. N. of Columbus. 

The Callais of Pliny was probably turquois. Pliny, in his 
description of it, mentions the fable that it was found in 
Asia, projecting from the surface of inaccessible rocks, 
whence it was obtained by means of slings. 

Receives a fine polish and is highly esteemed as a gem. 
The Persian king is said to retain for himself all the large 
and more finely-tinted specimens. The New Mexico locality 
affords fine gems. Prof. W. P. Blake regards the turquois 
as resulting from the decomposition of a trachyte. ‘The occi- 
dental or bone turquois is fossil teeth or bones, colored with 
a little phosphate of iron. Green malachite is sometimes sub- 
stituted for turquois; but it is softer, and different in color. 
The stone is so well imitated by art as scarcely to be detected 
except by chemical tests; but the imitation is much softer 
than true turquois. 


Childrenite. Orthorhombic; yellow to brown; hydrous phosphate, 


220 DESCRIPTIONS OF MINERALS. 


containing aluminium, iron, with little manganese. In crystals in 
Devonshire and Cornwall; Hebron, Me. 

Kosphorite. Has the crystalline form of childrenite, and contains 
the same constituents, but differs in being essentially a hydrous phos- 
phate of manganese with little iron; rose-red; G.=3°1-3°5. Branch- 


ville, Connecticut. 
Henwoodite. A hydrous aluminium-copper phosphate, of turquois 
blue color. Cornwall, on limonite. 


Wavellite. 


Orthorhombic. Usually in small hemispheres a third or 
half an inch across, finely radiated 
within ; when broken off they 
leave a stellate circle on the rock. 
Sometimes in rhombic crystals; 
also stalactitic. 

Color white, green, or yellowish 
and brownish, with a somewhat pearly or resinous lustre. 
Sometimes gray or black. ‘Translucent. H.=3°5-4. 
G. = 2°3-2°34. 

Composition. Al,O,,P,+12aq (or 3410,+2P,0,+12 aq) 
= Phosphorus pentoxide 35°16, alumina 38°10, water 26°74 
=100. 1 to 2 percent. of fluorine often present, replac- 
ing oxygen. B.B. whitens, swells, but does not fuse. 
Colors the flame green, especially if moistened with sul- 
phuric acid; moistened with cobalt nitrate, becomes blue 
after ignition; gives much water in the closed glass tube. 

Diff. Distinguished from the zeolites, some of which it 
resembles, by giving the reaction of phosphorus, and also 
by dissolving in acids without gelatinizing. Cacoxene, to 
which it is allied, becomes dark reddish brown B.B., and 
does not give the blue with cobalt nitrate. 

Obs. Slate quarries of York Co., Pa.; Washington Mine, 
Davidson Oo., N. C.; Magnet Cove, Ark. First discovered 
by Dr. Wavel in clay slate in Devonshire. Also in Bohe- 
mia and Bavaria. 




















——\ 
























aly 
=i 
. Be? 
iu By 


Zepharovichite is near wavellite. 

Liskeardite. A hydrous aluminium arsenate; incrusting; white, 
bluish. Cornwall. 

Mellite or Honey stone. In square octahedrons; honey-yellow; an 
aluminium mellate. Thuringia, Bohemia, Moravia, etc. 

Aluminium Carbonate.—Dawsonite. Hydrous aluminium-sodium 
carbonate, an analysis afforded Carbon dioxide 27°78, alumina 36°12, 
soda 22°86, water 18°24 = 100. From a felsyte dike near Montreal; 
Siena, Tuscany. 


CERIUM, YTTRIUM, ERBIUM, LANTHANUM, DIDYMIUM. 221 


CERIUM, YTTRIUM, ERBIUM, LANTHANUM, DIDYMIUM. 


Known in nature in the condition of fluorides, tanta- 
lates, columbates, phosphates, or carbonates, and also as 
constituents in several silicates. 


Yttrocerite. 


Massive. Color violet-blue (somewhat resembling purple 
fluorite); also reddish brown. Lustre glistening. Opaque. 
H=45. G.=3°43'5. 

Composition. Fluorine 25:1, lime 47:6, cerium protoxide 
18°2, yttria 9:1. B.B. alone infusible. 

Obs. From Finbo and Broddbo, Sweden; Mt. Mica, Me.; 
probably Worcester Co., Mass.; Amity, Orange Co., N. Y. 


Tysonite. Fluoride of cerium, lanthanum, and didymium, in wax- 
yellow, hexagonal crystals. Pilke’s Peak, Col. 

Fluocerite, Ftluocerine. Other fluorideS containing cerium. 
Sweden. 


Samarskite. 


Orthorhombic; 7A J = 122° 46’. Usually massive, with- 
out cleavage. Color velvet-black. Lustre shining submetal- 
lic. Streak dark reddish brown. Opaque. H.=5°5-6. 
G.=5:'6-5'8. 

Composition. Analyses of the American afford niobic and 
tantalic pentoxide, with sesquioxides of yttrium (12-15 per 
cent.), cerium, didymium, and lanthanum, iron, and oxide 
of uranium. The new metals terbium, decipium, phillipium 
have been reported from the samarskite. In the closed 
tube decrepitates and glows. B.B. fuses on the edges to a 
black glass. With salt of phosphorus in both flames, an 
emerald-green bead. 

Obs. At Miask, in the Ural; in masses, sometimes weigh- 
ing many pounds, at the Mica mines of Western N. Caro- 
lina, along with columbite; rare at Middletown, Ct. 

Nohlite and Vietinghofite are near samarskite. 

Fergusonite. Hydrous niobate of yttrium, erbium, cerium; brown- 
ish black; lustre brilliantly vitreous on a surface of fracture; B.B. in- 
fusible, but loses its color. Sweden; Cape Farewell, Greenland ; 
Rockport, Mass.; Burke and Mitchell cos., N. C. 

Kochelite. Near fergusonite. Silesia. 

Annerédite. Orthorhombic; black, metallic or submetallic; niobate 
of uranium, yttrium, thorium, cerium, etc. Annerédd, Norway. 

Yitro-tantalite. A tantalate and niobate of yttrium, erbium and 
iron; different varieties are the black, the yellow, and the brown or 


222 DESCRIPTIONS OF MINERALS. 


dark-colored; infusible. Ytterby, Sweden; Broddbo and Finbo, 
near Fahlun. 

Huxenite. A niobate and tantalate of yttrium, uranium, erbium, 
and cerium; massive; brownish black; streak reddish brown: B.B. in- 
fusible. Norway. 

Sipylite. A niobate and tantalate of erbium and yttrium, resembling 
fergusonite in aspect; stated to contain also phillipium and ytterbium. 
Amherst Co., Va. 

ischynite. Black to brownish yellow; resinous to submetallic; 
H.= 5-6; G.= 4'9-5'1; a niobate and titanate of cerium, thorium, lan- 
thanum, didymium, and erbium. Miask, Urals; Norway. 

Polymignite and Polycrase. Related to ‘eschynite, Norway. 

Pyrochlore, Microlite, Disanalyie, under CaLcrum, p. 234. 

Rogersite. A hydrous yttrium niobate; in whitish crusts, on samar- 
skite. From Mitchell Co., N. C. 


Monazite. 


Monoclinic; 7A J= 93° 10’, C= 76° 14’. Perfect and 
brilliant basal cleavage. Observed only in imbedded crystals. 

Color brown, brownish red; subtrans- 
parent to nearly opaque. Lustre vit- 
reous inclining to resinous. Brittle. 
H.=5. G. = 4°8-5-1. 

Composition. A phosphate of cerium, 

| lanthanum, yttrium, and didymium. 
2% B.B. colors the flame green when moist- 

|} ened with sulphuric acid and heated., 
‘Y Difficultly soluble in acids, 
; Diff. The brilliant easy transverse 
cleavage distinguishes monazite from 
sphene. 

Obs. Occurs near Slatoust, Russia; at Tavetsch and Bin- 
nenthal, Switzerland (Twrnerite); in the U. States in small 
brown crystals, disseminated through a mica schist at Nor- 
wich and Chester, Ct.; also at Portland, Ct.; Yorktown, 
Westchester Co., N. Y.: Alexander Co., and elsewhere, 
N. C.; Amelia Co., Va., "in masses of 8 pounds and less. 






Oryptolite. A cerium phosphate; in minute yellow six-sided prisms 
in apatite. Arendal, Norway. 

eae Phosphate of cerium, didymium, and calcium. Corn- 
wa 

Aenotime. Yttrium phosphate; tetragonal, aay cleavage perfect; 
yellowish brown; opaque; lustre resinous; H. = 4°60; ‘ 
infusible. Lindesnacs, Norway; Ytterby, Beelae rold- washings of 
Seen oa Ga.; McDowell and Alexander Cos., W C.; near Pike’s 

eak, Co 


MAGNESIUM. 220 


Bastnisite. A carbonate of cerium, lanthanum, and didymium, 
containing fluorine. Bastniis, Sweden; Pike’s Peak, Col. 
Rhabdophane (Scovillite). Hydrous phosphate of cerium, lanthanum, 
and didymium; in pink and brownish incrustations on manganese ore. 
Salisbury, Ct. Phosphocerite is the same. 
Rutherfordite. Blackish brown; vitreo-resinous. Rutherford Co., 
C 


CARRONATES.—Farisite. A carbonate containing cerium, lan- 
thanum, and didymium, with fluorine. New Granada. 

Lanthanite. WUydrous lanthanum carbonate; in thin minute tables 
or scales; whitish or yellowish. Bastniis, Sweden; Saucon Valley, 
Lehigh Co., Pa. 

Tengerite. Yttrium carbonate; in thin coatings. Ytterby. 

Allanite, Gadolinite, Keilhauite, Tscheffkinite, and Erdmannite are 
silicates containing cither cerium or yttrium. 


MAGNESIUM. 


Magnesium occurs, in nature, as an oxide and a hydrated 
oxide, and in the condition of sulphate, borate, nitrate, 
phosphate, carbonate, and silicate. 

The sulphates and nitrate of magnesia are soluble in 
water, and are distinguished by their bitter taste; the other 
native magnesian salts are insoluble. ‘The presence of mag- 
nesia in infusible species, when no metallic oxides are pre- 
sent, is indicated by a blowpipe experiment explained on 
page 98. 


Periclasite.—Periclase. Magnesium Oxide. 


Isometric. In small imbedded crystals, with cubic cleay- 
age. Color grayish to dark green. H. nearly6. G= 
3°674. 

Composition. MgO (or the same as for magnesia alba of 
the shops), with a little iron as impurity. B.B. infusible. 
Soluble in acids without effervescence. 

From Mount Somma, Vesuvius, Italy. 


Sellaite. 'Tetragonal; colorless; transparent; fuses in a candle; mag- 
nesium fluoride (MgF1). Geibroula, Piedmont. 


Brucite.—Magnesium Hydrate. 


Rhombohedral. In hexagonal *prisms and plates; thin 
foliated, the thin lamine easily separated ; also fibrous, re- 
sembling amianthus (Nemalite). Translucent. Flexible but 
not elastic. Lustre pearly. Color white, often grayish or 
greenish. H.=2°5. G. = 2°35-2°45. 

Composition. MgO,H, (or MgO + H,O)= Magnesia 69°0, 


224 DESCRIPTIONS OF MINERALS. 


water 310=100. B.B. infusible, but becomes opaque and 
alkaline. Soluble in hydrochloric acid without efferves- 
cence. Manganbrucite is a manganesian variety. 

Diff. Resembles talc and gypsum, but is soluble in 
acids ; differs from heulandite and stilbite also by its infusi- 
bility. 

Obs. Occurs in serpentine at Hoboken, N. J.; Staten 
Island, and Brewster’s, N. Y.; at Texas, Pa.; Swinaness, 
in Unst, one of the Shetland Isles. 


Pyroaurite (Iglestrémite). Magnesium-iron hydrate, silvery white 
to golden. Longban, Wermland; Scotland. 

Hydromagnestie. White pearly crystalline, or earthy, hydrous car- 
bonate of magnesia. Hoboken, N.J.; Texas, Pa.; and elsewhere. 

Spinel contains oxygen and magnesium along with aluminium. See 
page 213. Magnesium is also present in some magnetite, a variety of 
which is called Magneferrite. 

Nocerine. A magnesium.calcium fluoride; from Nocera tufa. 

Ohlormagnesite. Magnesium chloride from Vesuvius. Bischofite, 
from a salt-mine in Prussia, is probably the same. 

Carnallite. Hydrous magnesium-potassium chloride. Stassfurth. 

Tachhydrite. Hydrous magnesium-calcium chloride. Stassfurth. 


E:psomite.—Epsom Salt. Magnesium Sulphate. 


Orthorhombic; 7A J= 90° 34’. Cleavage perfect, parallel 
with the shorter diagonal. Usually in fibrous crusts or 
botryoidal masses. Color white. Lustre vitreous to earthy. 
Very soluble; taste saline bitter. 

Composition. MgO,8S + 7aq (or MgO + SO, = 7aq) = 
Sulphur trioxide 32°5, magnesia 16°3, water 51°2 = 100. 
Liquefies in its water of crystallization when heated. Gives 
much water, acid in reaction, in the closed tube. 

Diff. The fine spicula-like crystalline grains of Epsom 
salt, as it appears in the shops, distinguish it from Glauber 
salt, which occurs usually in thick crystals. 

Obs. Occurs as an efflorescence in the galleries of mines 
and elsewhere. Sometimes in minute crystals mingled with 
the earth of the floors of caves. In the Mammoth Cave, 
Ky., it adheres to the roof in loose masses like snowballs. 
The fine efflorescences suggested the old name hair-salt. 

Occurs dissolved in mineral springs at Epsom, in Surrey, 
England, and thence the name it bears; at Sedlitz, Aragon; 
in a grotto in Southern Africa, a layer an inch and a half 
thick; massive (/eeichardtite) at Stassfurth. 

Its medical uses are well known. It is obtained for the 


MAGNESIUM. 22d 


arts from the bittern of sea-salt works, but now chiefly 
from dolomite or magnesite, by decomposing with sulphuric 
acid. 


Polyhalite. Hydrous calcium-magnesium sulphate; massive, some- 
what fibrous in appearance; brick-red; taste weak. Bitter. Ischl and 
Other salt-mines. Arugite is similar. 

Ktveserite. ydrous magnesium sulphate. Stassfurth. 

Picromerite. Hydrous potassium-magnesium sulphate; white. 
Stassfurth. Kaznite, sulphato-chloride of same bases. 

Bledite. A hydrous sodium-magnesium sulphate. Salt-mines of 
Ischl ; near Mendoza. Stmonyite is related ; from Hallstadt. 

Leweite. A hydrous sodium-magnesium sulphate; contains more 
sulphur trioxide than Bleedite. Ischl. 


Boracite.—Magnesium Borate. 


Isometric. Usual in small cubes; with the alternate 
angles replaced, or with all 

1. replaced but four of them 2 
differently from the other 
four. Cleavage only in ip 
traces. Also massive. In 
crystals, translucent. Color 
white or grayish; yellowish 
orgreenish. Lustre vitreous. \ JA\ 
H. of crystals = 7; when 
massive, softer. G. = 2°97. Becomes electric when heated, 
with the opposite angles of the cube of opposite polarity. 

Composition. Mg,O,,.B, + MgCl, (or 3MgO + 4B,0, + 
4MegCl,) = Boron trioxide 62:0, magnesia 31°0, chlorine 
7-0 = 100. B.B. fuses easily with intumescence, coloring 
the flame green; globule crystalline on cooling. Dissolves 
in hydrochloric acid; wet with cobalt nitrate turns pink on 
ignition. 

Diff. Distinguished readily by its form, high hardness, 
and pyro-electric properties. 

Obs. With gypsum and common salt, near Liineburg in 
Saxony; near Kiel, Prussia; also at Stassfurth. 





Rhodizite. ike boracite in its crystals, but tinges the blowpipe 
flame deep red; supposed to be a Jime-boracite. With red tourmaline 
in Siberia. 

Ludwigite. A magnesium-iron borate; fibrous; dark green to black. 

Szaibelyite. A hydrous magnesium borate. Hungary. Pinnoite 
is another; Stassfurth. 

Warwickile. In rhombic prisms of 93° to 94°; hair-brown to black 


226 DESCRIPTIONS OF MINERALS. 


with sometimes a copper-red tinge; a magnesium-titanium borate. 
Edenville, N. Y., in crystalline limestone. 

Sussexite. A hydrous magnesium-manganese borate; fibrous and 
pearly; G. = 3°42. Mine Hill, Franklin Furnace, Sussex Co., N. J. 

Nitromagnesite. Magnesium nitrate; in white deliquescent efflores- 
cences, having a bitter taste. With calcium nitrate, m limestone 
caverns. Used, like its associate, in the manufacture of saltpetre. 

Wagnerite. A magnesium fluo-phosphate; yellowish or grayish ob- 
lique rhombic prisms; insoluble; H. = 5-5°5; G. =3'l. Salzburg, 
Austria. SAjerulfine is wagnerite. 

Newberyite. Orthorhombic tabular crystals, from guano; hydrous 
magnesium phosphate. Skipton Caves, Victoria. 

Hernisite and Resslerite. White hydrous magnesium arsenates. 

Liineburgite. A magnesium boro-phosphate. Liineburg. 


Magnesite.—Magnesium Carbonate. 


Rhombohedral; # : R =107° 29’. Cleavage rhombohe- 
dral, perfect. Often massive, either granular, or compact 
and porcelain-like, in tuberose forms; also fibrous. 

Color white, yellowish or grayish white, brown. Lustre 
vitreous; fibrous varieties often silky. Transparent to 
opaque. H.=3-4:5 G.=3; 3-3°2 when ferriferous. 

Composition. MgO,C (or MgO + CO,) = Carbon dioxide 
52°4, magnesia 47°6 = 100. B.B.infusible; after ignition, an 
alkaline reaction; nearly insoluble in cold dilute hydrochloric 
acid, but dissolves with effervescence in hot. 

Diff. Resembles some calcite and dolomite; but from a 
concentrated solution no calcium sulphate is precipitated 
on adding sulphuric acid. The fibrous variety is distin- 
guished from most other fibrous minerals by effervescence 
in hot acid, which shows it to be a carbonate. 

Breunnerite is a magnesite containing iron; turns brown 
on exposure. 

Obs. Usually associated with magnesian rocks, especially 
serpentine. At Hoboken, N.J., in fibrous seams; similarly 
at Lynnfield, Mass.; Texas, Pa.; Bare Hills, Md.; in Canada, 
at Bolton, massive and imperfectly fibrous, traversing white 
limestone. 

A convenient material for the manufacture of magnesium 
sulphate or Epsom salt, to make which requires simply 
treatment with sulphuric acid, and so used on a large scale 
in Maryland and Pennsylvania. 

Hydromagnesite. A. hydrous magnesium carbonate; contains about 
20 p. c. of water. With serpentine. Hoboken, N. J.; Texas, Pa. 


Hydrogtobertite is similar, but gave 29°93 p.c. of water and less 
CO;. From Pollenza, Italy. 


CALCIUM. 227 


CALCIUM. 


Calcium exists in nature in the state of fluorite, and this 
is its only native binary compound. It occurs in ternaries 
in the state of sulphate, borate, columbate, phosphate, ar- 
senate, carbonate, titanate, oxalate, and silicate. The car- 
bonate (calcite and limestone) is one of the three most abun- 
dant of minerals. The fluoridesand sulphate, and some 
silicates, are also of very common occurrence. 

With the exception of the calcium nitrate, none of the 
native salts of lime are soluble in water except in small 
proportions. Before the blowpipe they give no odor, and 
no metallic reaction; but they tinge the flame red; and 
many of them give up a part of their acid constituent, and 
become caustic and react alkaline. The specific gravity is 
below 3°2, and hardness not above 5, 


Fluorite.—Fluor Spar. Calcium Fluoride. 
Isometric; Figs. 1 to 4. Cubes most common. Cleavage 
octahedral, perfect. Rarely fibrous; often compact, coarse, 
or fine granular. 





Colors usually bright; white, or some shade of light 
green, purple, or clear yellow most common; rarely rose-red 
and, sky-blue; colors of massive varieties often banded. 
Transparent, translucent, or subtranslucent. H. = 4. 
G. = 3-325. Brittle. 

Composition. CaF’, = Fluorine 48°7, calcium 51°3 = 100. 
Phosphoresces when gently heated (as seen in the dark), 
affording light of different colors, as emerald-green, purple, 
blue, rose-red, pink, orange. 3B.B. decrepitates, and ulti- 
mately fuses to an enamel, having an alkaline reaction; 
treated in powder with sulphuric acid, hydrofluoric acid 
gas is given off which corrodes glass. Chlorophane is the 
kind affording a bright green phosphorescence. 


228 DESCRIPTIONS OF MINERALS. 


Diff. In its bright colors, fluorite resembles some of the 
gems, but its softness and its easy octahedral cleavage when 
crystallized at once distinguish it. Its strong phosphores- 
cence is a striking characteristic ; and also its affording 
easily, with sulphuric acid and heat, a gas that corrodes 

lass. 
; Obs. Fluorite occurs in gneiss, mica schist, clay slate, 
limestone, and sparingly in beds of coal either in veins or 
occupying cavities, or as imbedded masses. It is the 
gangue in some lead-mines. 

Cubic crystals of a greenish color, over a foot each way, 
have been obtained at Muscolonge Lake, St. Lawrence 
County, N. Y.; near Shawneetown on the Ohio, a beautiful 
purple fluor in grouped cubes of large size is obtained from 
limestone and the soil of the region; at Westmoreland, N. 
H., at the Notch in the White Mountains; Blue Hill Bay, 
Maine; Putney, Vt.; Lockport, N. Y.; Boulder Co., Cal.; 
Crystal Park, El Paso Co., Col.; Montana; Wyoming; N. 
Mexico; Pike’s Peak, Col. Chlorophane var. at Trumbull, 
Ct., and Amelia Court House, Va. 

In Derbyshire, England, abundant, and hence the name 
Derbyshire spar. A common mineral in the mining dis- 
tricts of Saxony. 

Calcium fluoride exists in the enamel of teeth, in bones, 
and some other parts of animals; also in certain parts of 
many plants; and by vegetable or animal decomposition it is 
afforded to the soil, to rocks, and also to coal-beds in which 
it has been detected. 

Massive fluorite receives a high polish, and is worked into 
vases and various ornaments in Derbyshire, England. 
Some of the varieties from this locality, consisting of rich 
purple bands alternating with yellowish white, are very 
beautiful. The mineral is difficult to work because brittle. 
Fluorite is also used to obtain hydrofluoric acid for etch- 
ing. To etch glass, a picture, or whatever design it is de- 
sired to etch, is traced in the thin coating of wax with 
which the glass is first covered; a very small quantity of the 
liquid hydrofluoric acid is then washed over it; on remoy- 
ing the wax, in a few minutes, the picture is found to be 
engraved on the glass. The same process is used for etch- 
ing seals, and any siliceous stone will be attacked with 
equal facility. ‘This application of fluor spar depends upon 
the strong affinity between fluorine and silicon. Fluor 


CALCIUM. 229 


spar is also used as a flux to aid in reducing copper and 
other ores, and hence the name flwor. 
Chlorocalcite (Hydrophilite). Calcium chloride. Vesuvius, Peru. 


Gypsum.—Hydrous Calcium Sulphate. 


Monoclinic; J A [ = 148° 42’; 20A 2i= 111° 42’. Fig. 
2, & common twin (or arrow-head) 
crystal. Cleavage parallel to broad 
face in Fig. 1, very easy, affording 
thin pearly flexible laminge; in a cross 
direction, imperfect. Also in lami- 
nated masses; fibrous, with a satin 
lustre; in stellated or radiating forms 
consisting of narrow lamine; also 
granular and compact. 

When crystallized usually trans- 
parent or nearly so; the massive, translucent to opaque. 

ustre pearly. Color white, » gray, yellow, reddish, brown- 
ish, and even black. H. = 1°5-2, or so soft as to be 
‘scratched by the finger-nail. G.= 2:33. The plates bend 
in one direction and are brittle in another. 

Composition. CaO,S+2aq (or CaO +80, + 2aq)= 
Sulphur trioxide 46 ‘5, lime 32 6, water 20:9= 100. B.B 
becomes instantly white and opaque and exfoliates: then 
fuses to a globule, having an alkaline reaction. Ina closed 
tube much water is given off. Dissolves quietly in hydro- 
chloric acid, and the solution gives a heavy precipitate with 
barium chloride. 

The principal varieties are as follows: 

Selenite: mn transparent plates or crystal. Named from 
selene, the Greek for moon, alluding to the pearl-white ap- 
pearance. 

Radiated and Plumose gypsum: radiated in structure. 

Fibrous gypsum, Satin spar: white and delicately fibrous. 

Snowy gypsum and Alabaster: include the white or light- 
colored compact gypsum having a very fine grain. 

Diff. Foliated gypsum resembles some varieties of heu- 
landite, stilbite, talc, and mica; and the fibrous looks like 
fibrous “carbonate of lime, asbestus and some of the fibrous 
zeolites; but gypsum in all its varieties is readily distin- 
guished by its softness; its becoming B.B. opaque white 
through loss of water without fusion ; ; by not effervescing 
or gelatinizing with acids. Moreover, on adding a little 





230 DESCRIPTIONS OF MINERALS. 


water to the powder obtained by heating, the water is taken 
up and the whole becomes solid. 

Obs. Gypsum forms extensive beds in certain limestones 
and clay beds, and also occurs in volcanic regions. Selenite 
and snowy gypsum occurs in limestone near Lockport, at 
Camillus, Manlius, and Troy, N. Y.; in Davidson Co., 
Tenn. ; crystals (Fig. 1), at Poland and Canfield, Ohio ; 
groups of crystals at St. Mary’s in Maryland; in Mammoth 
Cave, Ky., alabaster, in imitation of flowers, leaves, shrub- 
bery, and vines. Alabaster is obtained at Castelino in Italy, 
35 miles from Leghorn. Massive gypsum is abundant in 
N. York, from Syracuse to the western extremity of Gene- 
see County; in New Brunswick, especially at Hillsboro’, 
where part is excellent alabaster ; in Hants, Colchester, and 
other districts, Nova Scotia; in Ohio, Michigan, Illinois, 
Virginia, Tennessee, Kansas, Arkansas, Texas, lowa; and in 
connection with the Triassic beds of the Rocky Mountain 
region, abundant in Nevada, California, Colorado, Montana, 
Dakota, N. Mexico, Arizona. Abundant also in Hurope. 

Gypsum, when calcined and reduced to powder, is plas- 
ter of paris, and is used for taking casts, making models, 
and for giving a hard finish to walls. Alabaster is cut into 
vases and various ornaments, statues, etc. It owes its 
beauty for this purpose to its snowy whiteness, translucency, 
and fine texture. Moreover, owing to its softness, it can 
be cut or carved with common cutting instruments. Ground 
gypsum is used for improving soils. 


Anhydrite.—Anhydrous Calcium Sulphate. 
Orthorhombic; J A J= 100° 30’; 1¢4A 17=85° and 95°. 
In rectangular and rhombic prisms; cleaves easily in three 
directions, into square blocks. Also fi- 
rr brous and lamellar, often contorted; coarse 

fos <j 1. and fine granular, and compact. 
Color white, or tinged with gray, red, 


v 


12 


7 or blue. Lustre more or less pearly. 
22-~7|9, ‘Transparent to subtranslucent. H.= 
iz 8-3°5. G. = 2:95-2:97. 


Composition. CaO,S (or CaO + 8O,) = 

pys—_1t__/7] 8. Sulphur trioxide 58°8, lime 41°2=100. 
Itisan anhydrous calcium sulphate. B.B. 

and with acids, its reactions are like those 

of gypsum, except that in the closed tube it gives no water. 


CALCIUM. 231 


A scaly massive variety containing a little silica has been 
named Vu/pinite; contorted concretionary kinds are some- 
times called 7ripestone. Anhydrite is called by miners 
hard-plaster, because harder than gypsum. 

Diff. Its square forms of crystallization and its breaking 
or cleaving into square blocks are good distinguishing char- 
acters; it looks as if the crystallization were cubic; but 
there is some difference in the ease of cleavage in the 
three directions. 

Obs. Fine blue with gypsum and cale spar in black lime- 
stone at Lockport, N. Y.; near Windsor, N. Scotia; at 
Hillsboro’", N. Brunswick. Foreign localities are at the 
salt-mines of Bex in Switzerland, Hall in the Tyrol, Ischl 
in Upper Austria, Wieliczka in Poland, and elsewhere. 

The yulpinite variety is sometimes cut and polished for 
ornamental purposes. 


Hittringite. Hydrous calcium-aluminium sulphate; in minute hexag- 
onal crystals. District of Laach, in limestone. 


Ulexite.—Boronatrocalcite. Calcium-sodium Borate. 


In interwoven fibres, or capillary crystals, making small 
rounded masses. H.=1. G.=1°65. Lustre silky. Color 
white to gray. Tasteless. 

Composition. Hydrous calcium-sodium borate. B.B. 
fuses very easily; wet with sulphuric acid and heated B.B. 
the flame is momentarily deep green. 

Obs. From the dry plains of Iquique, and in Tarapaca, 
between Peru and Chili; Windsor, Brookville, and New- 

ort, N. Scotia; Columbus Marsh and Thiel Salt Marsh, 

ey., alternating with layers of salt. 

Valuable as a source of borax. Franklandite is similar ; 
from Peru. 

Bechilite. A hydrous calcium borate. Occurs as an incrustation at 
the Tuscan lagoons, Italy. A ‘‘ hydrous borate of lime” reported by 
Hayes from Iquique, Peru, has been called Hayesine; but its compo- 
sition has been questioned, it being referred to Ulexite. 

Priceite. A hydrous calcium borate; white, chalky; G. = 2°262; 
formula deduced Ca30,;B.: + 6aq (or 83CaO + 4BO; +6 aq). Forms a 
compact layer and large masses, 5 m. N. of Chetko, in Curry Co., 
Oregon. Cryptomorphite may be the same as priceite; and if so has 
priority in name. Windsor, N. Scotia. 

Pandermite. Like priceite; H. = 8; G. = 2°48; formula deduced 
Ca.0::B;-+3aq. In gray gypsum. Panderma, Black Sea. 

Colemanite. Like pandermite in formula except 5 aq for 3 aq. 


22 DESCRIPTIONS OF MINERALS. 


monoclinic; in fine glassy crystals, white to colorless, and massive; 
o aes G. = 2°43, San Bernardino Co. and Death Valley in Inyo 

o:, Cal. 

Hydroboracite. A hydrous calcium-magnesium borate, resembling 
gypsum in aspect. 

Howlite. A hydrous calcium borate containing silica; Windsor, 
Nova Scotia ; called also Stlicoborocaleite. 


Scheelite.—Calcium Tungstate. 


Tetragonal. Also massive. Lustre vitreous, inclining 
to adamantine. Color white, pale yellowish, brownish, 
greenish, reddish. ‘Transparent-translucent. H. = 45-5. 
G. = 5°9-6:1. 

Composition. CaO,W (or Ca + WO,). B.B. fuses with 
much. difficulty to a transparent glass. Cuproscheelite has 
part of the calcium replaced by copper. 

Diff. Unlike calcite, and other minerals like it, in its high 
specific gravity, and non-effervescence with acids. 

Obs. From Monroe, Ct.; Flowe Mine, N. C.; with gold, 
at Warren Mine, Idaho, and Golden Queen Mine, in 
Colorado; in Mammoth Mining Dist., Nev.; Seattle, Wash- 
ington T.; Caldbeck Fell, England; in Bohemia; Hartz; 
Saxony; Hungary; Sweden; Vosges; Adelong, N. 8. W. 


Apatite.—Calcium Phosphate. 


Hexagonal. Usually in hexagonal prisms; OA1= 
139° 42’. Cleavage imperfect. Occasionally massive ; 
sometimes mammillary with a compact fibrous structure. 
Color usually greenish, often yellowish green, 
bluish green, and grayish green ; sometimes 
yellow, blue, reddish, brownish, colorless. 
Lustre vitreous to subresinous. Transpar- 
ent to opaque. H.=5. G. =3:18-3°25. 
Brittle. 

Composition.. Ca,O,P, + 4Ca(Cl,, F.) (or 
38CaO + P.O, + 4Ca(Cl,, EE) ements without 
fluorine, Phosphorus pentoxide 40°92, lime 
53°80, chlorine 6°82 = 100. When chlorine is present in 
place ‘of fluorine it is called chlor-apatite, and when the re- 
verse, fluor-apatite. B.B. infusible except on the edges. 
Dissolves slowly in nitric acid without effervescence. Some 
varieties phosphoresce when heated, and some become elec- 
tric by friction. Its constituents are contained in the bones 





CALCIUM. 230 


and ligaments of animals, and the mineral has probably been 
derived in many cases from animal remains.* 

Massive apatite is often called Phosphorite; the pale yel- 
lowish-green crystals, Asparagus stone. Osteoliteis a white 
earthy apatite. Hupyrchroite is a fibrous mammillary variety 
from Crown Point, Essex Co., N. Y. 

Fossil excrements, called coprolites, occur in stratified 
rocks, and the material sometimes constitutes extensive 
beds; it is chiefly calcium phosphate. Guano is of this 
origin, and consists of calcium phosphate along with more 
or less of hydrous phosphates and some impurities. 

Diff. Distinguished from beryl by its inferior hardness, 
it being easily scratched with a knife; from calcite by no 
effervescence with acids; from pyromorphite by its difficult 
fusibility, and giving B.B. no metallic reaction. 

Ols. Apatite occurs in gneiss, mica schist, hornblende 
schist, granular limestone. In microscopic crystals it is 
sparingly present in almost all crystalline rocks, the ig- 
neous. as well as metamorphic. The best crystals in the 
United States occur in granular limestone. 

Large deposits occur in veins in the Archean of Canada, 
especially the Ottawa region, which contain also much 
calcite and pyroxene, hornblende, phlogopite mica, and 
often zircon, titanite, scapolite, and other minerals. Some 
of the crystals of apatite in the veins are one to two 
feet in diameter, and weigh hundreds of pounds. ‘The 
veins are extensively worked, producing 20,000 to 25,000 
tons a year. 

Other localities are Edenville and Amity, Orange Co., 
N. Y.; Westmoreland, N. H., in a vein of feldspar and 
quartz; Blue Hill Bay, Auburn, Me.; Bolton, Chester- 
field, Chester, Mass.; beautiful blue at Dixon’s quarry, 
Wilmington, Del. 

Named from the Greek apatao, to deceive, in allusion to 
the mistake of early mineralogists respecting the nature of 
some of its varieties. 

When abundant, used, like guano, as a fertilizer, on ac- 
count of its phosphoric acid. To make it capable of being 
taken up by plants it is treated first with a small portion of 
sulphuric acid, which renders the phosphoric acid soluble. 


* Bones contain 25 per cent. of calcium phosphate, with some fluoride of cal- 
cium, 3 to 12 per cent. of calcium carbonate, some magnesium phosphate and 
sodium chloride, besides 33 per cent. of animal matter. 


234 DESCRIPTIONS OF MINERALS. 


When guano has been accumulated by birds, or other ani- 
mals, over coral rock, a calcium carbonate, (as on some 
coral islands,) the waters in filtrating through it have often 
carried down the soluble phosphoric acid or phosphates 
mie the underlying beds, turning them into calcium phos- 
phate. 


Spodiosite is probably an apatite pseudomorph. 

Herderite. Calcium-beryllium fluo-phosphate; orthorhombic; yel- 
lowish, greenish white. Ehbrenfriedersdorf, Saxony; Stoneham, Me. 

Brushite and Metabrushite. WHydrous calcium phosphates. Found 
in guano. Monetite and monite are other guano substances. 

yrophosphorite. A white, earthy phosphate; analysis gave it the 
composition of a pyrophosphate. A guano deposit in the W. Indies, 

Pharmacolite. A hydrous calcium arsenate. 

Haidingerite. Another hydrous calcium arsenate. 

Berzeliite. Calcium-magnesium arsenate; isometric; yellow; G. = 
4-41. Caryinite is related in composition but is not isometric. Both 
from Longban, Sweden. 

Nitrocaleite. Wydrous calcium nitrate. From caverns. 

Pyrochlore. A calcium-cerium niobate; in small brown and brown- 
a yellow isometric octahedrons; G. = 4'3-4°5. Norway; Miask, 

iberia. 

Microlite. In isometric octahedrons, like pyrochlore; color brown; 
G. = 5 5-6, in composition a calcium tantalate. Chesterfield, Mass.; 
Branchville, Ct.; Amelia Co., Va., Uté, Sweden. The crystals first 
found were small, whence the name; but some Virginia crystals weigh 
four pounds, 

Disanalyte. A columbate and titanate of calcium, cerium, and iron; 
in cubes. The Kaiserstuhl, in granular limestone. 

Romette, Calcium antimonate; tetragonal; yellow. 

Atopite Another calcium antimonate in isometric crystals. Swe- 
den. Schneedergite is another. 


Calcite.—Calc Spar. Calcium Carbonate. 


Rhombohedral; # A f (Fig. 1) =105° 5’. Cleavage 
easy, parallel with #. Often fibrous; lustre silky ; some- 
times lamellar; often coarse or fine granular, and com- 

act. 

: Color, when transparent, colorless, topaz-yellow, and 
rarely rose or violet; other crystalline varieties, white, gray, 
reddish, yellowish, rarely deep red, often mottled; when 
massive uncrystalline, of various dull shades, chalk-white, 
grayish white, gray, ochre-yellow, red, brown, and black. 
Lustre vitreous ; of the finely fibrous, silky; of the uncrys- 
talline, dull, often earthy. H.=3. G.of pure crystals 
2°715 5 2°5-2°8, 


CALCIUM. 235 


Composition. Ca0,C (or CaO + CO,) = Carbon dioxide 
44, lime 56 = 100. Sometimes impure from mixture with 
other substances. B.B. infusible; colors the flame reddish ; 
gives up its carbon dioxide, and becomes caustic, and alka- 
line in reaction; and by this process, carried on in lime- 


Oe | 


7h 


kilns, limestone is burnt to guicklime. Effervesces in dilute 
cold hydrochloric acid. Many varieties phosphoresce when 
heated. 

The following are the principal varieties : 

Iceland spar. ‘Transparent crystalline calcite; formerly 
brought in large crystals from Iceland. 

Dog-tooth spar. Has the form in Fig. 7. 

Satin spar. Finely fibrous, with a satin lustre. Usually 
in veins. 

Limestone. A general name for massive calcite as well 
as for massive dolomite. 

Granular limestone. Lustre glistening, owing to its con- 
sisting of crystalline grains; the grains show the cleavages 
of crystals of calcite. Hence called crystalline limestone. 
The better kinds, valuable in the arts, are called marble; 
the coarser of them, architectural marble; the finer white, 
statuary marble; colored kinds, as well as white, when 
polished, ornamental marbles. The best marble is as white 
and fine-grained as loaf-sugar, which it much resembles. 
wee impure with pyrite, mica, tremolite, and other min- 
erals. 

Compact limestone. Dull in lustre unless polished, and 





236 DESCRIPTIONS OF MINERALS. 


not distinctly granular in texture. Colors sometimes ar- 
ranged in blotches or veins. ‘The kinds that are handsome 
when polished and fit for ornamental purposes are included 
among marbles. 

Chalk. White and earthy; without lustre; so soft as 
to leave a trace on a board. Forms mountain beds. Most 
chalk was made chiefly out of the shells of Rhizopods. 

, Hydraulic limestone (Cement stone). An impure lime- 
‘stone affording, on burning, a quicklime that will make a 
cement that sets under water (p. 459). 

Oolite, Pisolite. Odlite is a compact limestone, consist- 
ing of small round concretionary grains, looking like the 
spawn of a fish; the name is derived from the Greek odn, 
anegg. Pisolite, a name derived from pisum, the Latin 
for pea, differs from odlite in being coarser; the spherules 
often have a concentric structure, and thus show their con- 
cretionary origin. 

Argentine. A white shining limestone consisting of la- 
mine a little waving, and containing some silica. 

Fontainebleau limestone. ‘This name is applied to crys- 
tals of the form shown in figure 3, containing a large pro- 
portion of sand, and occurring in groups. ‘They were for- 
merly obtained at Fontainebleau, France, but the locality 
is exhausted. 

Rock milk. White and earthy like chalk, but still softer, 
and very fragile. Deposited from waters containing lime 
in solution. Sock meal is a powdery variety. 

Calcareous tufa. Formed by deposition from waters like 
rock milk, but more cellular or porous and not so soft. 

Stalactite, Stalagmite. 'The name stalactite is explained 
on page 60. The deposits of the same origin that cover 
the floors of caverns are called stalagmite. ‘They generally 
consist of differently colored layers, and appear banded or 
striped when broken. ‘The so-called ‘‘Gibraltar rock” is 
stalagmite from a cavern in the rock of Gibraltar. 

Thinolite. Calcite pseudomorphs, of prismatic and 
pyramidal forms, abundant in thick deposits in the basins 
of old lakes over the Great Basin west and southwest of the 
Great Salt Lake. 

Travertine. Deposits from calcareous waters forming 
thick beds, as in the Gardiner River region of the Yellow- 
stone Park, Tivoli (Tibur of the Romans) near Rome, 
where it was early called Tiburtine, and in many other 
regions. 


CALCIUM. 237 


Stinkstone, Anthraconite. Gives out a fetid odor when 
struck; caused by certain bituminous materials present in 
the rock. 

Diff. Distinguished by being scratched easily with a 
knife; its strong effervescence in dilute acid; its com- 
plete infusibility. Less hard than aragonite, unlike it also 
in having a very distinct cleavage. 

Obs. Calcite occurs in fine crystals at Rossie, N. Y., one 
crystal from there, now in the Peabody Museum at New 
Haven, weighing 165 pounds; in geodes of ‘‘dog-tooth 
spar” in limestone at Lockport, along with gypsum and 
pearl spar; at Leyden and Lowville, N. Y; at Bergen Hill, 
N. J., in beautiful wine-yellow crystals in amygdaloidal 
cavities; at the Lake Superior copper-mines; and else- 
where. Argentine occurs near Williamsburg and South- 
ampton, Mass. Rock milk covers the sides of a cave at 
Watertown, N. Y., and is now forming. Stalactites of 
great beauty occur in Luray, Weir’s, and other caves in Vir- 
ginia and in the Western States. Chalk occurs in England 
and Europe; also in Western Kansas. Granular limestones 
are common in the Hastern and Atlantic States, and com- 
pact limestones in the Middle and Western States, and 
some beds of the former afford excellent marble for building 
and some of good quality for statuary. 

In the state of quicklime, it is mixed with water and sand 
to make ‘‘ mortar;” a calcium hydrate results which becomes 
slowly carbonated through carbonic acid in the atmosphere. 
See further the chapter on Rocks. 


Aragonite. 


Orthorhombic; 7A J = 116° 10’.. In rhombic prisms; 
usually in compound crystals having the form of a hexag- 
onal prism, with uneven or striated sides; or in stellated 
forms consisting of two or three flat crystals crossing one 
another. ‘Transverse sections of some of the compound 
crystals are shown in Figs. 1 to 4. Cleavage parallel to J, 
not very distinct. Also in globular and coralloidal shapes; 
also in fibrous seams in rocks. 

Color white, or with light tinges of gray, yellow, green, 
and violet. Lustre vitreous. Transparent to translucent. 
H. =3°5-4. G. = 2°93-2°936. 

Composition. Same as for calcite; and B.B. with acids 
the same, except that it falls to powder readily when heated. 


238 DESCRIPTIONS OF MINERALS. 


Diff. Distinguished from calcite by the absence of the 
cleavage of the latter, as well as the crystalline form; also 
by its higher specific gravity. 

Obs. Aragonite occurs mostly in gypsum beds and in 
connection with iron ores; also in basalt and other rocks. 





The coralloidal forms are found in iron ore beds, and are 
called Flos ferri, flowers of iron. ‘They look like a loosely 
intertwined or tangled white cord. 

The jlos-ferri variety occurs at Lockport with gypsum; 
at Edenville, at the Parish ore bed in Rossie, N. Y., and 
in Chester Co., Pa. Aragon in Spain affords six-sided 
prisms, associated with gypsum; hence the name of the 
species. Also at Bilin, in Bohemia; Tarnowitz, in Silesia ; 
and other places. 


Dolomite.—Calcium-Magnesium Carbonate. Magnesian Limestone. 


Rhombohedral; RA & = 106°15’. Cleavage perfect par- 
allelto R. Faces of rhombohedrons sometimes 
curved, as in the annexed figure. Often gran- 
y ular and massive, constituting extensive beds, 

Color white, or tinged with yellow, red, 
green, brown, and sometimes black. Lustre vit- 
reous or pearly. Nearly transparent to trans- 
lucent. Brittle. H.=3%5-4. G. = 2°8-2°9. 

Composition. %3CastMgO,C (or ($Cas4Mg)O + CO,) = 
Calcium carbonate 54:35, magnesium carbonate 45°65 = 
100. Some iron or manganese is often present, replacing 
part of the magnesium or calcium. Iron-bearing varieties 
» become brown on exposure, and the manganese-bearing, 
black, yielding as the ultimate result generally limonite, 
and oxide of manganese. 

The principal varieties of this species are as follows: 





CALCIUM. 239 


Dolomite. White, crystalline granular, often not distin- 
guishable in external characters from granular limestone. 

Pearl spar. In pearly rhombohedrons with curved faces. 

Rhomb spar, Brown spar. In rhombohedrons, which 
become brown on exposure, owing to their containing 1 to 
10 per cent. of oxide of iron or manganese. 

A cobaltiferous variety has a red tint. A white compact 
siliceous variety has been called Gurhofite. Some hydraulic 
limestones are dolomite. 

Diff. Distinctive characters nearly the same as for cal- 
cite. It is harder than that species, and differs in the 
angles of its crystals, and effervesces in acids very feebly, 
unless heated; but chemical analysis is often required to 
distinguish them. 

Obs. Common as marble in western New England and 
southeastern New York, and constitutes much of that used 
for building; and the uncrystalline constitutes many of the 
limestones of New York and the States farther west and 
south. Orystallized specimens have been obtained at the 
Quarantine, Richmond Co., N. Y.; large at Brewster, 
N. Y., and Alexander Co., N. C.; rhomb spar occurs in tale, 
at Smithfield, R. I.; Marlboro’, Vt.; Middlefield, Mass.; 
pearl spar in crystals of the above form at Lockport, Ni- 
agara Falls, Rochester, Glen’s Falls; gurhofite on Hustis’s 
farm, Phillipstown, N. Y. 

Dolomite was named in honor of the geologist and trav- 
eller Dolomieu. 

Burns to quicklime like calcite. The white massive 
variety is used extensively as marble. The magnesian lime 
has been supposed to injure soils; but this is believed not 
to be the case if it is air-slaked before being used. It is 
employed in England in the manufacture of Epsom salts or 
magnesium sulphate.. 

Ankerite. Resembles brown spar, and, like that, becomes brown 
on exposure. RA R= 106° 12’. A calcium-magnesium-iron-manga- 
nese carbonate. The Styrian iron ore beds of Saltzburg are some of 
its foreign localities. Occurs in Nova Scotia; in quartz veins in 
western New Hampshire; Quebec, Canada, etc. Parankerite is a 
variety of it. 

Hydrodolomite. A calcium-magnesium carbonate containing water. 
Pennite from Texas, Pa., is similar. 

Whewellite. Calcium oxalate. In monoclinic crystals, England ; 


coal-bed near Dresden. 
Thaumasite. Mixture of carbonate and sulphate. Sweden. 


240 DESCRIPTIONS OF MINERALS. 


BARIUM anp STRONTIUM. 


Barium and strontium occur in nature only in anhydrous 
ternary compounds of the following kinds: sulphate, car- 
bonate, silicate; and in silicates only in combination with 
other basic elements. ‘The species are characterized by high 
specific gravity, ranging from 3°5 to 4:8. Strontium gives 
a red color to the blowpipe flame; and barium, if strontium 
an other basic elements are absent, a characteristic green 
color. 


Barite.—Heavy Spar. Barytes. Barium Sulphate. 


Orthorhombic; 7A =101° 40’; OA4¢7=1415 08’; 
O A 1i = 127° 18’. Forms as in figures. Cleavage I, O, 
perfect. Massive varieties often 


coarse lamellar; also columnar, 

Ba IV fibrous, oranular, and compact. 

Color white, sometimes tinged 

yellow, red, brown, blue, or dark 

aap lf brown. Lustre vitreous; some- 
times pearly. ‘Transparent or 

translucent. H. = 2°5-3°5. G. 
= 4°3-4°7; 4°48 of pure crystals. 

Composition. BaO,S (or BaO 
-+ SO,) = Sulphur trioxide 343, 
baryta 65°7 = 100. Strontium 
and calcite are sometimes pres- 
ent replacing a little barium. 
B.B. fuses to a bead which reacts alkaline; imparts a green 
color to the flame. After fusion with soda in the reducing 
flame on coal, if placed on a silver coin and moistened, it 
produces a black stain, due to sulphur. 

Diff. Distinguished by its specific gravity, the inaction 
of acids, and its hardness. 

Often present in mineral veins as the gangue of the ore. 
Occurs in this way, and also by itself, at Cheshire, Ct.; 
Hatfield, Mass.; Rossie and Hammond, N. Y.; Perkiomen, 
Pa., and the lead-mines of the ] Mississippi Valley. Sco- 
harie, and Pillar Point near Sackett’s Harbor, are other 
localities; also near Fredericksburg, Marion, and Irvington, 
Va; N. ‘Scotia, ete. 

“* Barytes,” or barite, is ground up and used to adulterate 








BARIUM AND STRONTIUM. 241 


white lead. When white lead is mixed in equal parts with 
it, it is sometimes called Venice white, and another quality 
with twice its weight of barite is called Hamburg white, 
and another, one-fourth white lead, is called Dutch white. 
When the material is very white, a proportion of it gives 
greater opacity to the color, and protects the lead from 
being speedily blackened by sulphurous vapors; and these 
mixtures are therefore preferred for certain kinds of paint- 
ing. 20,000 tons are ground up annually in the U. States. 


Dreelite. A barium-calcium sulphate. Beaujeu, France. 


Witherite.—Barium Carbonate. 


Orthorhombic; 7A 7=118° 30’. Cleavage imperfect. 
Also in globular or botryoidal forms; often massive, and 
either fibrous or granular. Color 1 9 
yellowish or grayish white to white : ° 
when in crystals. ‘Translucent to > 

transparent. Lustre a little resin- ie 
ous when massive. H. = 3-4, G. ¢ 
= 4:29-4:35, Brittle. YW Ee 

Composition. BaO,C (or BAO WW eae 
+ CO,) = Carbon dioxide 22:3, 8. 
baryta 77°7 = 100, B.B. decrepi- 
tates; fuses easily, tinging the £ 
flame green, toa translucent glob- { 
ule, which becomes opaque on 
cooling, and colors moistened tur- 
meric paper red, ffervesces in 
hydrochloric acid. 

Diff. Distinguished, by its specific gravity and fusibility, 
_ from calcite and aragonite; by its action with acids, from 
allied minerals that are not carbonates; by yielding no 
metal, from cerussite, and by tingeing the flame green, 
from strontianite, 

Obs. Important foreign localities are Fallowfield in 
Northumberland (where it is mined), Alstonmoor in Cum- 
berland, Anglezark in Lancashire; Silesia; Styria; Sicily. 
In the U, States, Lexington, Ky. 

Witherite, from Fallowfield, is used in chemical works, 
in the manufacture of plate-glass, and in France in the 
manufacture of beet sugar, | 

16 


<>: 





242 DESCRIPTIONS OF MINERALS. 


Barytocalcite. Barium-calcium carbonate; in monoclinic crystals; 
white; H. = 4; G. = 3°6-3°7. Alston-Moor, England. 

Bromlite, Of same composition, but orthorhombic. Bromley Hill, 
and Northumberland, England. 

Nitrobarite. Barium nitrate; soluble. Chili. 


Celestite.—Strontium Sulphate. 


Orthorhombic; JA 7= 103° 30’ to 104° 30’. Crystals 
rhombic prisms or tabular; often long and slender. Cleay- 
age distinct parallel with J. 
Also columnar or fibrous; 
rarely granular. Color 
white; slightly bluish; some- 
times clear white or reddish. 
Lustre vitreous or a little 
pearly. Transparent to translucent. H. = 3-3°. G.= 
3°9-4, Brittle. 

Composition. SrO,8 (or SrO + SO,) = Sulphur trioxide 
43°6, strontia 56-4 = 100. B.B. decrepitates and fuses, 
tingeing the flame bright red, to a milk-white globule, giv- 
ing an alkaline reaction. With soda on coal fuses to a mass 
which when moistened blackens silver. 

Diff. Differs from barite, by the bright red color of the 
flame B.B., and its less specific gravity; and from the car- 
bonates, by not effervescing with acids. 

Obs. Found in beds of sandstone or limestone, and also 
with gypsum, rock salt, and clay. Bluish tabular and 
prismatic crystals, at Strontian Island, Lake Erie; Schoharie, 
Lockport, and Rossie, N. Y.; handsome fibrous at Frank- 
town, Huntingdon County, and Bell’s Mills, Blair Co., Pa. 
Sicily affords fine crystallizations associated with sulphur. 

The pale sky-blue tint, so common with the mineral, gave 
origin to the name celestite. 

Used in the arts for making nitrate of strontia, which is 
employed for producing a red color in fireworks. 





Strontianite.—Strontium Carbonate, 


Orthorhombic; JA f= 117° 19’. Cleavage parallel to J, 
nearly perfect. "Also fibrous and eranular; sometimes in 
globular shapes, radiated within. 

Color pale greenish white; also white, gray, and yellow- 
ish brown. Lustre vitreous, or somewhat resinous, “‘Trans- 





POTASSIUM AND SODIUM. 243 


parent to translucent. H. = 3°5-4. G. = 3°6-3°72. 
Brittle. 

Composition. SrO,C (or SrO + CO,) = Carbon dioxide 
29°7, strontia 70°3 = 100. Some strontium often replaced 
by calcium. B.B. swells, throws out little sprouts, but does 
not fuse. Colors the flame bright red; after heating, pos- 
sesses an alkaline reaction. Effervescesin cold dilute acid; 
sulphuric acid gives a precipitate of strontium sulphate. 

Diff. Its effervescence with acids distinguishes it from 
minerals that are not carbonates; the color of the flame 
B.B., from witherite and other carbonates; calcium salts 
also give a red color to the flame, but the shade is yellowish 
and less brilliant. 

Obs. In limestone at Schoharie, N. Y., both in crystals, 
fibrous, and massive; in Jefferson Co., N. Y.; Mifflin Co., 
Pa. Strontian in Argyleshire, England, was the first 
locality known, and gave the name to the mineral, whence 
the metal strontium; occurs there, with galenite, in stellated 
and fibrous groups, and in crystals. 

Used for preparing the strontium nitrate. 


POTASSIUM anp SODIUM. 


Potassium and sodium occur in nature in the state of 
chloride, sulphate, nitrate, and carbonate, and are constitu- 
ents in many silicates. 


Sylvite.—Potassium Chloride. 


Isometric; crystals often cubes with octahedral planes 
Fig. 8, p. 19). White or colorless. Lustre vitreous. 
‘aste nearly that of common salt. H.=2. G. =1°9-2. 

Composition. KCl = Chlorine 47°5, potassium 52°5 = 

100. From Vesuvius and Stassfurt. 
Other potassium chlorides containing iron, p. 200. 


Halite.—Common Salt. Sodium Chloride. 


Isometric. In cubes, and related forms. Sometimes in 
shallow concave hopper-shaped crystals formed by the en- 
largement at the margin of a floating crystal. Cleavage 
cubic, perfect. 

Color white or grayish, sometimes rose-red, yellow, and 
of amethystine tints. Taste saline. H.=2. G. = 2°257. 


244 DESCRIPTIONS OF MINERALS, 


Composition. NaCl = Chlorine 60:7, sodium 39°3 = 100. 
Crackles or decrepitates when heated; fuses easily, coloring 
the flame deep yellow. A variety from Chili (Huantajayite) 
contains 11 p. c. of silver chloride. 

Diff. Distinguished by its solubility and taste. 

Obs. Occurs in extensive but irregular beds, usually asso- 
ciated with gypsum, anhydrite, and clays or sandstone. 
Exists in formations of all ages, from the Silurian to the 
present time. Found in the Pyrenees, in the valley of 
Cardona, and elsewhere, forming hills 300 to 400 feet high; 
in Poland and Wieliczka; at Hall in the Tyrol, and along 
a range through Reichenthal in Bavaria, Hallein in Salz- 
burg, Hallstadt, Ischl and Ebensee in Upper Austria, and 
Aussee in Styria; in Hungary at Marmoros and eisewhere; 
in Transylvania, Wallachia, Galicia, and Upper Silesia; at 
Vic and Dieuze in France; at Bex in Switzerland; in 
Cheshire, England; in Northern Africa in vast quantities, 
forming hills and extended plains; in Northern Persia at 
Tiflis; in India in the province of Lahore and in the valley 
of Cashmere; in China and Asiatic Russia; in South Amer- 
ica, in Perv and the Cordilleras of New Granada. 

Among the most remarkable deposits are those of Poland 
and Hungary. ‘The former, near Cracow, have been worked 
since the year 1251, and it is calculated that there is still 
enough salt remaining to supply the whole world for many 
centuries. Its deep subterranean regions are excavated into 
houses, chapels and other ornamental forms, the roof being 
supported by pillars of salt; and when illuminated by lamps 
and torches they are objects of great splendor. 

The salt is often impure with clay, and is purified by dis- 
solving it in large chambers, drawing it off after it has 
settled, and evaporating it again. The salt of Norwich (in 
Cheshire) is in masses 5 to 8 feet in diameter, which are 
nearly pure, and it is prepared for use by crushing it be- 
tween rollers. 

In North America, beds of rock salt exist at Goderich in 
Canada; at Wyoming and other places in western New 
York (reached by boring to a depth of 1000 feet or more); 
in West Virginia on the Great Kanawha, etc.; extensively 
at Petite Anse, La., where it underlies 144 acres; in Nevada, 
Montana, Utah, Wyoming, Idaho, Dakota, New Mexico, 
California; in the Salmon River Mts., Oregon. 

Brine springs also proceed from rocks of various ages ; 





‘ 
etn wi 


POTASSIUM AND SODIUM. 245 


and often they are indications of deep-seated beds of rock 
salt. 

The salt of western New York, and Goderich, Canada, 
is of the Salina period of the Upper Silurian; the brine 
springs of Michigan, Ohio, and Kanawha, from shales and 
marlytes of the Carboniferous age; those of the salt beds of 
Norwich, England, in magnesian limestone of the Permian; 
those of the Vosges and of Salzburg, Ischl, and the neigh- 
boring regions, in marly sandstone of the Triassic; those of 
Bex, in Switzerland, in the Lias formation; that of Wie- 
liczka, Poland, and the Pyrenees, in the Cretaceous or Chalk 
formation; that of Catalonia, in the Tertiary; that of 
Louisiana, in the Quaternary, and large deposits are still 
more recent; and, besides, there are lakes that are now 
evaporating and producing salt depositions. 

Vast lakes of salt water exist in many parts of the world. 
The Great Salt Lake of Utah has an area of 2000 square 
miles, and is remarkable for its extent, considering that it 
is situated at an elevation of 4200 feet above the sea. The 
dry regions of the Great Basin and of Southeastern Cali- 
fornia are noted for salt licks and lakes. In Northern 
Africa large lakes as well as hills of salt abound, and the 
deserts of this region and Arabia abound in saline efflores- 
cences. The Dead and Caspian seas, and the lakes of 
Khoordistan, are salt. From 20-26 parts in a hundred of 
the weight of the water from the Dead Sea are solid salts, 
of which 10 parts are common salt. Over the pampas of 
La Plata and Patagonia there are many ponds and lakes of 
salt water. 

The greater part of the salt made in Eastern North 
America is obtained by evaporation from salt springs, and 
Michigan and New York are the chief sources. At the 
best springs at Syracuse, N. Y., a bushel of salt is obtained 
from every 40 gallons. But the discovery of rock salt at 
Wyoming, and elsewhere west of Syracuse, may make the 
brines of New York of comparatively little value. 

The process of evaporation under the heat of the sun is 
extensively employed in hot climates for making salt from 
sea water, which affords a bushel for every 300 or 350 gal- 
lons. or this purpose a number of large shallow basins 
are made adjoining the sea; they have a smooth bottom of 
clay, and all communicate with one another. ‘The water is 
let in at high tide and then shut off for the evaporation to 


246 DESCRIPTIONS OF MINERALS. 


goon. This is the simplest mode, and is used even in un- 
civilized countries, as among the Pacific Islands. 

The salt product of the U. States in 1884 was about 
32,575,000 bushels (or a fifth of this number of barrels); 
of which 15,810,000 was from Michigan, 8,940,000 from 
New York; 1,750,000 from Ohio, and 1,600,000 from W. 
Virginia. In 1885, it was 35,200,000 bushels. 


Mirabilite.—Glauber Salt. Hydrous Sodium Sulphate. 


Monoclinic. (Figure, p. 42.) In efflorescent crusts of a 
white or yellowish-white color; also in many mineral waters. 
Taste cool, then feebly saline and bitter. 

Composition. Na,O,S + 10 aq (or Na,O + SO, + 10 aq) 
= Sulphur trioxide 24°8, soda 19°3, water 55-9 = 100. 

Diff. Distinguished from Epsom salt, for which it is 
sometimes mistaken, by its coarse crystals, and the yellow 
color it gives to the blowpipe flame. 

Manufactured from common salt, its production being 
one stage in the manufacture of sodium carbonate. 

Obs. From Aussee, Austria; Sicily; Tarapaca; etc.; on 
Hawaii, in a cave at Kailua, where it is now forming; 1 
efflorescences on the limestone below Genesee Falls, Ree 
Rochester, N. Y.; Sweetwater Valley, Wyoming; Morrison, 
Cal.; New Mexico. 

The artificial salt was first made by a German chemist 
by the name of Glauber. 

Aphthitalite (Arcanite). Potassium sulphate, K.0,8 = Sulphate tri- 
oxide 45°9, potash 54°1=100. Vesuvius. 

Misenite. ydrous potassium sulphate. A cavern near Misene. 

Thenardite. Sodium sulphate, Na,O,S = Sulphur trioxide 43°7, 
soda 56°3 = 100. Spain; Bolivia; Tarapaca, in Peru; Siate Range, 
San Bernardino Co., Cal.; in Nevada; on the Rio Verde, Arizona. 

Glauberite. Sodium-calcium sulphate: in monoclinic crystals. 
Villa Rubia, in New Castile; Aussce, Austria; and other salt beds. 

Syngenite. Hydrous potassium- -calcium sul; phate. East Galicia. 

Watievillite. Hydrous sodium- potassium - calcium sulphate, 
Bavaria. 

Tarapacaite. Potassium chromate; yellow. Tarapaca. 


Borax.—Hydrous Sodium Biborate. Tinkal. 


Monoclinic; JA J= 87°. Cleavage parallel with 7-7 per- 
fect. Crystals white or colorless; often transparent; lustre 
vitreous. H. = 2-2°5. G.=1°716. ‘Taste sweetish-alka- 
line. 


ee _ - a 


POTASSIUM AND SODIUM. 247 


Composition. Na,O,B,-+10 aq (or Na,O + 2B,0, + 
10 aq) = Boron trioxide 36°6, soda 16°2, water 47°2 = 100. 
B.B. swells up to many times its bulk, becomes opaque 
white, and finally fuses to a glassy globule. 

Obs. Originally brought from a salt lake in Thibet, where 
it is dug in masses from the edges and shallow parts of the 
lakes; deposition is now going on. Crude borax was 
formerly sent to Europe under the name of ¢tinkal, 
and there purified for the arts. Also found in Asiatic 
Turkey, Peru, and Ceylon. Has been extensively made 
from the boracic acid of the Tuscan lagoons by the reac- 
tion of this acid on sodium carbonate. ‘The borax of com- 
merce is in part made from ulexite and lime-borate (p. 231). 

Occurs under like circumstances in California and 
Nevada, or is manufactured from other borates in solution. 
Localities in California are Clear Lake and vicinity; 
near Walker’s Pass, Sierra Nevada; at Mono and Owens 
Lakes, and at Death Valley, in Inyo Co., Cal., near the 
borders of Nevada; in the Slate Range Marsh, in San 
Bernardino Co., Cal.; in Churchill Co., Nev.; at Little 
Salt Lake, near Ragtown, on the Pacific Railroad, and in 
Esmeralda Co., at Columbus, T'eel’s and Rhodes’ Marshes, 
and in Fish Lake Valley. The large deposits of “‘ priceite” in 
Southern Oregon, and of ulexite (p. 231) in the ‘‘ Cane 
Spring District,” 20 miles west of San Bernardino, and at 
the Columbus Marsh, are other sources of borax. ‘The 
amount of California and Nevada borax produced in 1876 
was 5,180,910 lbs.; in 1880, 3,860,748 lbs.; in 1882, 4,236,- 
291 Ibs.; in 1884, 7,000,000 lbs.; in 1885, 8,000,000 lbs. 


Tincalconite. Efflorescence on borax. California. 


Nitre.— Potassium Nitrate. 


Orthorhombic; 7A 7=118° 50’. In modified right 
rhombic prisms. Usually in thin, white crusts, and in 
acicular crystals. Taste saline and cooling. H.=2. G. 
eed) te 

Composition. KO,N (or K,O + N,O,) = Nitrogen pen- 
toxide (N,O,) 53°4, potash 46°6. Burns vividly on a live 
coal. 

Diff. Distinguished by the taste, and vivid action on a 
live coal; and from sodium nitrate, which it most resembles, 
by not becoming liquid on exposure to the air. 


248 DESCRIPTIONS OF MINERALS. 


Obs. Occurs in many of the caverns of Kentucky and 
Indiana, etc., scattered through the earth that forms the 
floor of caves, and in many of the States and Territories of 
the far West. In procuring it, the earth is lixiviated, and 
the lye, when evaporated, yields the nitre. 

India is its most abundant locality, where it is obtained 
largely for exportation. This salt forms on the ground in 
the hot weather succeeding copious rains, and appears in 
silky tufts or efflorescences; these are brushed up by a kind 
of broom, lixiviated, and after settling, evaporated and 
crystallized. In France, Germany, Sweden, Hungary, and 
other countries, there are artificial arrangements called 
nitriarves or nitre beds, from which nitre is obtained by 
the decomposition mostly of the nitrates of lime and mag- 
nesia which form in these beds. Refuse animal and vege- 
table matter putrefied in contact with calcareous soils pro- 
duces nitrate of lime, which affords the nitre by reaction 
with carbonate of potash. Old plaster lixiviated affords 
about 5 per cent. ‘T'his last method is much used in France. 
Nitrification takes place through the agency of a peculiar 
kind of microscopic plant, related to the bacteria. 

Nitre, called also saltpetre, is employed in making gun- 
powder, forming 75 to 78 per cent. in shooting powder, and 
62 in mining powder. ‘The other materials are sulphur (10 
per cent. for shooting powder to 20 for mining) and char- 
coal (12 to 14 for shooting powder and 18 for mining). It 
is also extensively used in the manufacture of nitric and 
sulphuric acids; also for pyrotechnic purposes, fulminating 
powders, and sparingly in medicine. 


Nitratine.—Soda Nitre. Sodium Nitrate. Cubic Nitre. 


Rhombohedral; R: R= 106° 33’. Also in crusts or 
efflorescences, of white, grayish, and brownish colors. Taste 
cooling. Soluble and very deliquescent. 

Composition. NaO,N (or Na,O + N,O,) = Nitrogen pen- 
toxide 63°5, soda 36°5 = 100. Burns vividly on coal, with 
a yellow light. 

Diff. Resembles nitre (saltpetre), but deliquesces, and 
gives a deep yellow light when burning. 

Obs. In the district of Tarapaca, Northern Chili, it 
covers the dry Pampa for an extent of forty leagues, mixed 
with gypsum, common salt, glauber salt, and remains of 


x ois 
pot > — LO 


a ie hes nd 


AMMONIUM. 249 


recent shells; in Humboldt Co., Nev.; New Mexico; near 
Calico, Cal. 

Used extensively in the manufacture of nitric acid; also 
in making nitre by replacing the sodium by potassium. 


Natron.—Hydrous Sodium Carbonate. Carbonate of Soda. 


Monoclinic. Generally in white efflorescent crusts, some- 
times yellowish or grayish. Taste alkaline. Hffloresces on 
exposure, the surface becoming white and pulverulent. 

Composition. Na,O,C + 10 aq (or Na,O + CO, + 10 aq) 
= Carbon dioxide 26°7, soda 18°8, water 54:5 = 100. 
Effervesces strongly with acids. 

Diff. Distinguished from other soda salts by effervescing, 
and from trona, by efflorescing on exposure. 

Ods. Found in solution in certain waters, from which it 
is crystallized in efflorescences by evaporation. Abundant 
in the soda lakes of Egypt; also in lakes at Debreczin, in 
Hungary; in the alkali flats of the Great Basin, abundant; 
in Carbon Co., Wyoming, where are over 100 soda lakes, 
20 to 300 acres in area, and 15 to 45 feet deep. 

This salt (but the artificially prepared) is extensively 
used in the manufacture of soap and glass, and for many 
other purposes. 

Trona. Wydrous sodium sesquicarbonate. Occurs in the province 
of Suckenna, in Africa, between Tripoli and Fezzan, constituting a 
fibrous layer an inch thick beneath the soil; abundant at a lake in 
Ue 48 miles from Mendoza; an extensive bed in Churchill 

o., Nev. 

Lhermonatrite. Hydrous sodium carbonate, Na2O;C + aq. 

Gay-Lussite. White; brittle; monoclinic; composition 4+Na}CaQOs 
C+24aq. Lagunilla, in Maracaibo; Little Salt Lake, near Ragtown, 


ev. 
Hanksite. Sodium sulphato-carbonate in hexagonal crystals. 
California. 


AMMONIUM. 


The salts of ammonia are more or less soluble in water, 
and are entirely and easily volatilized before the blowpipe. 
When treated with caustic lime or potassa, ammonia is lib- 
erated, and is recognized by its odor and the reaction of the 
vapors on test papers. 


Salmiak.—Sal Ammoniac, Ammonium Chloride. 
In white crusts or efflorescences, often yellowish or gray. 


250 DESCRIPTIONS OF MINERALS. 


Translucent—opaque. Taste saline and pungent. Soluble 
in three parts of water. 

Composition. NH,Cl = Chlorine 66°3, ammonium 33:7 
= 100. Gives off the odor of ammonia when powdered and 
mixed with quicklime. 

Obs. Occurs in many volcanic regions, as at Etna, Vesu- 
vius, and the Sandwich Islands, where it is a product of 
voleanic action. Occasionally found about ignited coal 
seams. 

Sal ammoniac is one of the products found in the soot 
and smoke of both wood and coal fires. The sal ammoniac 
of commerce was formerly manufactured from animal 
matter or coal soot. In Egypt, whence the greater part of 
this salt was obtained, the fires of the peasantry are made 
of the dung of camels; and the soot which contains a con- 
siderable portion of the ammoniacal salt is preserved and 
carried in bags to the works, where it is obtained by subli- 
mation. But the ammoniacal liquor of the gas-works 
affords crude sulphate of ammonium, and from it, the sal 
ammoniac of commerce is now obtained by subliming a mix- 
ture of this sulphate with common salt (sodium chloride). 

A valuable article in medicine. Employed by tinmen in 
soldering to prevent the oxidation of copper surfaces, and 
also in a variety of metallurgical operations. 


Mascagnite. A hydrous ammonium sulphate; in mealy crusts, of a 
yellowish-gray or lemon-yellow color; translucent; taste pungent and 
bitter; composition (NH:;)20.,8 + H.O = Sulphur trioxide 63°3, am- 
monia 22°8, water 23°9; easily soluble in water. Etna; Vesuvius; 
the Lipari Islands; the Guafiape Isles, in guano. One of the products 
from the combustion of anthracite coal. 

Lecontite. Hydrous ammonium-sodium sulphate. Near Comay- 
agua, Central America. 

Boussingaultite, hydrous ammonium-magnesium sulphate. Tus- 
cany. Hannayite is another, in triclinic crystals, from guano in 
Victoria, with struvite. 

Structie. Hydrous ammonium-magnesium phosphate; in yellowish 
crystals, slightly soluble in water. Found on the site of an old church 
in Hamburg, where there had been quantities of cattle dung. 

Tschermigite. An ammonia alum. Tschermig, Bohemia; Utah 
Co., Utah. 

Larderellite. A white, tasteless, ammonium borate. Tuscan la- 

oons, 
3 Hydrous ammonium phosphate and Ammonium bicarbonate (Tesche- 
macherite) have been detected in guano; also, Hydrous sodium-am- 
monium phosphate, called Stercorite. 

Cryptohalite. A probable ammonium fluosilicate. Vesuvius. 


HYDROGEN—WATER. 251 


HYDROGEN. 


Hydrogen is the basic constituent in hydrochloric acid, 
and in water. 


Hydrochloric Acid.—Muriatic Acid, Hydrogen Chloride. 


A gas, consisting of Chlorine 97°26, hydrogen 2°74 = 100 
= HCl. It has a pungent odor, and is acrid to the skin. 

Rapidly dissolved by water. Passed into a solution of 
nitrate of silver, it produces a white precipitate (silver 
chloride) which soon blackens on exposure. Passes off 
whenever common salt is acted on by sulphuric acid; occa- 
sionally formed about volcanoes. 


Hydrofluorite. Hydrofluoric acid or hydrogen fluoride. An ema- 
nation at some eruptions of Vesuvius, as observed by Scacchi. 


WATER. 


Water (hydrogen oxide) is the well-known liquid of 
streams and wells. The purest natural water is obtained by 
melting snow, or receiving rain in a clean glass vessel; but 
it is absolutely pure only when procured by distillation. 
It consists of hydrogen 1 part by weight, and oxygen 8 
parts, or hydrogen 11°11, oxygen 88°89 = 100. It becomes 
solid at 32° Fahrenheit (or 0° Centigrade), and then crys- 
tallizes, and constitutes ice or snow. ‘The crystals are of 
the hexagonal system. Flakes of snow consist of a congeries 
of minute crystals, and stars, like the figures on page 4, may 
often be detected with a glass. Various other allied forms 
are also assumed. ‘The rays meet at an angle of 60°, and 
the branchlets pass off at the same angle with perfect regu- 
larity. The density of water is greatest at 39°:2 F.; below 
this it expands as it approaches 32°, and in the state of ice 
it is only 0°920. It boils at 212° F. A cubic inch of pure 
water at 62° I’. and 30 inches of the barometer, weighs 
252°458 grains, which equals 16.386 grams; and a cubic 
foot of water weighs 62°355 pounds avoirdupois. <A pint, 
United States standard measure, holds just 7342 troy grains 
of water, which is little above a pound avoirdupois (7000 
grains troy). 


252 DESCRIPTIONS OF MINERALS. 


Water, as it occurs on the earth, contains some atmo- 
spheric air, without which the best would be unpalatable. 
This air, with some free oxygen also present, is necessary 
to the life of aquatic animals. In most spring water there 
is a minute proportion of salts of calcium (sulphate, chloride 
or carbonate), often with a trace of common salt, carbonate 
of magnesium, and some alumina, iron, silica, phosphoric 
acid, carbonic acid, and certain vegetable acids. These 
impurities constitute usually from ;1, to 10 parts in 10,000 
parts by weight. ‘The water of Long Pond, near Boston, 
contains about } a part in 10,000; the Schuylkill of Phila- 
delphia, about 1 part in 10,000; the Croton, used in New 
York City, 1 to 1} parts in 10,000. Nitric acid is usually 
found in rain-water combined with ammonia; river-waters 
are ordinarily the purest of natural waters, unless they have 
flowed through a densely populated region. 

Sea-water contains from 32 to 37 parts of solid substances 
in solution in 1000 parts of water. The largest amount in 
the Atlantic, 36°6 parts, is found under the equator, away 
from the land or the vicinity of fresh-water streams; and 
the smallest in narrow straits, as Dover Straits, where there 
are only 32°5 parts. In the Baltic and Black Seas the pro- 
portion is only one third that in the open ocean. Of the 
whole, one half to two thirds is common salt (sodium chlo- 
ride). -‘The other ingredients are magnesium salts (chloride 
and sulphate), amounting to four fifths of the remainder, 
with sulphate and carbonate of calcium, and traces of bro- 
mides, iodides, phosphates, borates, and fluorides. ‘The 
water of the British Channel affords water 964-7 parts in 
1000, sodium chloride 27:1, potassium chloride 0°8, mag- 
nesium chloride 3°7, magnesium sulphate 2°30, calcium 
sulphate 1°4, calcium carbonate 0°03, with some magnesium 
bromide and probably traces of iodides, fluorides, phosphates 
and borates. The bitter taste of sea-water is owing to the 
salts of magnesium present. 

The waters of the Dead Sea contain 200 to 260 parts of 
solid matter in 1000 parts (or 20 to 26 per cent.), including 
% to 10 per cent. of common salt, the same proportion of 
magnesian salts, principally the chloride, 24 to 33 per cent. 
of calcium carbonate and sulphate, besides some bromides 
and alumina. ‘The density of these waters is owing to this 
large proportion of saline ingredients. 

Mineral waters vary much in constitution. They often 


SILICA. | 253 


contain iron in the state of bicarbonate, like those of Sara- 
toga and Ballstown, and are then called chalybeate waters, 
Hydrogen sulphide is often held in mineral waters and im- 
parts to them its odor and taste; such are the so-called sz/- 
phur springs. 

Minute traces of salts of zinc, arsenic, lead, copper, silver, 
antimony, and tin have been found in some waters. What- 
ever is soluble in a region through which waters flow will 
of course be taken up by them, and many ingredients are 
soluble in minute proportions which are usually described 
as insoluble. 


Ill. SILICA AND SILICATES. 
1. SILICA. 


Quartz. 


Rhombohedral; RA R= 94° 15’. Usually in six-sided 
prisms, terminating in six-sided pyramids. No cleavage 
apparent, seldom even in traces; but sometimes obtained 
by heating and plunging the crystal into cold water. 


Ps fem 


Sometimes in coarse radiated forms; also coarse and fine 
granular (sandstone-like); also compact, crypto-crystalline 
(flint-like), either amorphous, or presenting stalactitic and 
mamuillary shapes. 

Often colorless; sometimes topaz-yellow, amethystine, 
rose, smoky, or other tints; also of various shades of yellow, 
red, green, blue, and brown colors to black; in some varieties 
the colors in bands, stripes, or clouds. Of all degrees of 
transparency to opaque. Lustre vitreous; of crystals 
splendent; of some massive forms, dull, often waxy. H. 
=%. G, = 2°5-2°8; pure crystals 2°65. 

Composition. SiO, = Oxygen 53°33, silicon 46°67 = 100. 
B.B. infusible ; with soda, fuses with effervescence, 





254 DESCRIPTIONS OF MINERALS. 


The common mineral impurities are chlorite, rutile, asbes- 
tus, actinolite, tourmaline, hematite, hmonite. Hematite 
(red iron oxide) is the usual red coloring matter; limonite, 
mostly in the state of yellow ochre, the yellow and brownish 
yellow; chlorite and actinolite give a green color, and an 
oxide or silicate of nickel, an apple-green tint; manganese 
an amethystine; carbonaceous matters, such as color marsh 
waters, smoke-brown shades. Quartz crystals often con- 
tain liquids in cavities, either water, petroleum or naphtha- 
like material, or liquid carbon dioxide (p.__). . Chalcedony 
usually has more or less of disseminated opal; and clear 
quartz is sometimes spangled with scales of mica or 
rendered opaline by means of asbestus. [lint or chert are 
often colored by mixture with the material of the enclosing 
TOC as 

Diff. Quartz is exceedingly various in color and form, 
but may be distinguished, by (1) absence of true cleavage; 
(2) its hardness; (3) its infusibility before the blowpipe; 
(4) its insolubility with either of the common acids; (5) its 
effervescence when heated B.B. with soda; and (6) when 
crystallized, by the forms of its crystals, which are almost 
always six-sided prisms terminating in six-sided pyramids. 

The varieties of quartz owe their peculiarities either to 
crystallization, mode of formation, or impurities, and they 
fall naturally into three series. | 

I. The vitreous varieties, distinguished by their glassy 
fracture. 

II. The chalcedonic varieties, having a subvitreous or a 
waxy lustre, and generally translucent. ; 

Ill. The jaspery cryptocrystalline varieties, having 
barely a glimmering lustre or none, and opaque. 


I. VITREOUS VARIETIES. 


Rock Crystal. Pure pellucid quartz. G. = 2°65. 

To this mineral the word crystal was first applied by the 
ancients; it is from the Greek Arustallos, meaning ice. 
The pure specimens are often cut and used in jewelry, 
under the name of ‘‘ white stone.” It is also used for 
optical instruments and spectacle-glasses. Even in ancient 
times it was made into cups and vases. Nero is said to 
have dashed to pieces two cups of this kind on hearing of 
the revolt that caused his ruin, one of which cost him a sum 
equal to $3000. 


SILICA. | 259 


Amethyst. Purple or bluish-violet, and often of great 
beauty. It was called amethyst on account of its supposed 
preservative powers against intoxication. When finely and 
uniformly colored, highly esteemed asa gem. G. = 2°65- 
2°66. 

Rose Quartz. Pink or rose-colored. Seldom occurs in 
crystals; generally in masses much fractured, and imper- 
fectly transparent. The color fades on exposure to the 
light, and on this account it is little used as an ornamental 
stone, yet is sometimes cut into cups and vases. G. = 2°65, 

False Topaz. Light yellow pellucid crystals. Often cut 
and set for topaz. Absence of cleavage distinguishes it 
from true topaz. The name citrine, often applied to this 
variety, alludes to its yellow color. 

Smoky Quartz. Crystals of a smoky tint; the color is 
sometimes so dark as to be nearly black and opaque except 
in splinters. It is the cairngorm stone. G. = 2°65-2°66. 

Milky Quartz. Muilk-white, nearly opaque, massive, and 
of common occurrence. Has often a greasy lustre, and is 
then called greasy quartz. G. = 2°64-2°66. 

Prase. lLeek-green, massive; resembling some shades of 
beryl in tint, but easily distinguished by the absence of 
cleavage and its infusibility. 

Aventurine Quartz. Common quartz spangled through- 
out with scales of golden-yellow mica. Usually translucent, 
and gray, brown, or reddish brown in color. 

Ferruginous Quartz Opaque, and either of yellow, 
brownish-yellow, or red color, from the presence of iron 
oxide. 

II, CHALCEDONIC VARIETIES. 


Chalcedony. ‘Translucent, massive, with a glistening 
and somewhat waxy lustre; usually of a pale grayish, blu- 
ish, whitish, or light brownish shade. Often occurs lining 
or filling cavities in amygdaloidal and other rocks. The 
cavities are little caverns into which siliceous waters have, 
at some period, filtrated and deposited their silica. The 
stalactites of chalcedony were pendants from the roof of 
the cavity. Some of these chalcedony grottos are several 
feet in diameter. Large geodes of this kind occur in the 
Keokuk limestone in Illinois and Iowa. 

Ohrysoprase. Apple-green chalcedony; colored by 
nickel. 


256 DESCRIPTIONS OF MINERALS. 


Carnelian. Bright red chalcedony, of a clear, rich tint. 
Cut and polished and much used in the more common 
jewelry, and for seals and beads. 7 

Sard. A deep brownish-red chalcedony, of a blood-red 
color by transmitted light. 

Agate. A variegated chalcedony. The colors are dis- 
‘ tributed in clouds, spots, or concentric bands. ‘These bands 
take straight, circular, or zigzag forms; and when the last, 
it is called fortification agate, so named from the resem- 
blance to the angular outlines of a fortification. These 
bands are the edges of layers of chalcedony, and these layers 
are the successive deposits during the process of its forma- 
mation. Mocha stone or Moss agate is a brownish agate, 
consisting of chalcedony with dendritic or moss-like delin- 
eations, of an opaque yellowish-brown color. All the 
varieties of agate are beautiful stones when polished, but 
are not much used in fine jewelry. ‘The colors may be 
darkened by boiling the stone in oil, and then dropping it 
into sulphuric acid; a little oil is absorbed by some of the 
layers, which becomes blackened or charred by the acid. 
Agates are sometimes artificially colored blue and of other 
shades. 

Onyx. A kind of agate having the colors arranged in 
flat horizontal layers; the colors are usually light clear 
brown and an opaque white. When the stone consists of 
sard and white chalcedony in alternate layers, it is called 
sardonyx. Onyx is the material used for cameos, and is 
well fitted for this kind of miniature sculpture. The figure | 
is carved out of one layer and stands in relief on another. 
A noted ancient cameo is the Mantuan vase at Brunswick. 
It was cut from a single stone, and has the form of a cream- 
pot, about 7 inches high and 23 broad. On its outside, 
which is of a brown color, there are white and yellow groups 
of raised figures, representing Ceres and Triptolemus in 
search of Proserpine. 

Cat’s Hye. Greenish-gray translucent chalcedony, hay- 
ing a peculiar opalescence, or glaring internal reflections, 
like the eye of a cat, when cut with a spheroidal surface. 
The effect is owing to filaments of asbestus. It comes from 
Ceylon and Malabar, ready cut and polished, and isa gem 
of considerable value. Other hard minerals having similar 
opalescence are included under the name. 

Flint, Hornsione, Chert. Massive compact silica, of dark 


7 


SILICA. 257 


shades of smoky gray, brown, or even black, feebly trans- 
lucent, breaking with sharp cutting edges and a conchoidal 
surface. Ilint occurs in nodules in chalk; not unfrequently 
the nodules are in part chalcedonic. Hornstone differs from 
flint in being more brittle, but is essentially the same 
thing; it is often found incommon limestone. Chert isan 
impure hornstone. Limestones containing hornstone or 
chert are often called cherty limestone. 

Plasma. A faintly translucent variety of chalcedony ap- 
proaching jasper, of a green color, sprinkled with yellow 
and whitish dots. 


Ill, JASPERY VARIETIES. 


Jasper. A dull opaque red, yellow, or brownish siliceous 
rock. It also occurs of green and other shades. Riband 
jasper is a jasper consisting of broad stripes of green, yel- 
low, gray, red, or brown. gyptian jasper consists of these 
colors in irregular concentric zones, and occurs in nodules, 
which are often cut across and polished. Lwin jasper isa . 
variety with delineations like ruins, of some brownish or 
yellowish shade on a darker ground. Porcelain jasper is 
nothing but a baked clay, and differs from jasper in being 
fusible before the blowpipe. Red felsyte resembles red 
jasper; but this is also fusible, and consists largely of 
feldspar. 

Jasper admits of a high polish, and is a handsome stone 
for inlaid work, but is not much used as a gem. 

Bloodstone or Heliotrope. Deep green, slightly trans- 
lucent, containing spots of red, which have some resem- 
blance to drops of blood. Contains a few per cent. of clay 
and iron oxide mechanically combined with the silica. 
The red spots are colored with iron. ‘There is a bust of 
Christ in the royal collection at Paris, cut in this stone, in 
which the red spots are so managed as to represent drops 
of blood. 

Lydian Stone, Touchstone, Basanite. Velvet-black and 
opaque, and used, on account of its hardness and black 
color, for trying the purity of the precious metals; this is 
done by comparing the color of the mark left on it with 
that of an alloy of known character. The effect of acids 
upon the mark is also noted. 

Besides the above there are other varieties arising from 
structure. 

17 


258 DESCRIPTIONS OF MINERALS. 


Tabular Quartz. Consists of thin plates, either parallel 
or crossing one another and leaving large open-cells. 

Granular Quartz. A rock consisting of quartz grains 
compactly cemented. ‘The colors are white, gray, flesh-red, 
yellowish, or reddish brown. It is a hard siliceous sand- 
stone. Ordinary sandstone often consists of nearly pure 
quartz. 

Pseudomorphous Quartz. Quartz under the forms of 
calcite, barite, fluorite, or other mineral. Shells, corals, 
etc., are sometimes found converted into quartz by the 
ordinary process of petrifaction. 

Silicified Wood. Petrified wood often consists of quartz, 
quartz having taken the place of the original wood. In 
some specimens the wood is converted into chalcedony and 
agate of various colors, having great beauty when polished. — 

Quartz with penetrating crystallizations. ‘The kinds are 
as numerous as the kinds of penetrating minerals. Rutile, 
asbestus, actinolite, and tourmaline sometimes occur in 
capillary or acicular forms, and give a specimen much in- 
terest. The delicate needles of rutile, in such cases, must | 
have existed in the rock cavity attached to its sides by one 
or both ends, and the quartz afterward became deposited 
about them; cut specimens sometimes used in jewelry are 
called in French //éches d’amour. 

Obs. Quartz is a constituent of granite, gneiss, mica 
schist, and many other common rocks, and the chief or 
only constituent of many sandstones, and of the sands of 
most sea-shores Fine quartz crystals occur in Herkimer 
Co., New York, at Middlefield, Little Falls, Salisbury, and 
Newport, in the soil and in cavities in a sandstone. 'The 
beds of iron ore at Fowler and Hermon, St. Lawrence Co., 
afford dodecahedral crystals. Diamond Island, Lake 
George, Pelham, and Chesterfield, Mass.; Paris and Perry, 
Me.; Meadow Mt., Md.; and Hot Springs, Arkansas, are 
other localities. ose quartz is found at Albany, Paris, 
Stow, Me.; Acworth, N. H.; and Southbury, Ct. Smoky 
guartz at Goshen, Mass.; Paris, Me.; in Burke and Alex- 
ander Cos., N. Carolina; at Pike’s Peak, Col. (whence it 
is largely exported); and elsewhere. Amethyst at Bristol, 
R. I.; Delaware and Chester Cos., Pa.; Keweenaw Point, 
Lake Superior; Clayton, Rabun Co., Ga.; in Arizona; 
Nevada. Chalcedony and agates in Nova Scotia, poor near 
Northampton, and along the trap of the Connecticut 


SILICA. 259 


Valley—finer near Lake Superior, upon some of the 
Western rivers, and in Oregon. Chrysoprase occurs at 
Belmont’s lead-mine, St. Lawrence Co., N. Y., and a green 
quartz (often called ‘chrysoprase) at New Fane, Vt., along 
with fine drusy quartz. Heliotrope occupies veins in slate 
at Bloomingrove, Orange County, N. Y.  Silveified wood, 
much of it agatized, abundant near Holbrook, Arizona 
(whence it is now procured for polishing), California, Colo- 
orado, Valley of the Yellowstone, etc. 

Switzerland, Dauphiny, Piedmont, the Carrara quarries, 
and numerous other foreign localities furnish fine crystals. 

The silica of the feldspars, owing to the alkali present 
with it—either potash, soda, or lime—is easily dissolved by 
hot waters (those of geysers and hot springs), and a solution 
of alkaline silicate is thus made, much like the soda-silicate 
of the shops called soludle silica or water-glass. From such 
solutions quartz has been deposited extensively in the rocks 
of the globe, in fissures making quartz veins; in cavities 
small and large, making geodes of chalcedony, agate, or of 
quartz crystals, or filling the cavities solid; or silicifying 
wood. Some porous kinds of igneous rocks or lavas 
(trachytes and allied kinds), and especially the beds made 
of volcanic débris or tufas, undergo alteration easily through 
the action of percolating waters, “and little heat is required 
for it; and where volcanic débris (ashes, scoria) have 
covered forests, the trees of the forests have been silicified 
over large areas, as in California, Arizona, and Nevada. 
The feldspar in the change is converted into kaolin, and in 
the process a fourth to a third of the silica is set free; be- 
sides, pyroxene or hornblende, if present, loses also as large 
a part of the silica; consequently the supply of discharged 
silica is very large. ‘The liberated silica, besides making 
quartz, often makes opal, another form of silica; and this 
is the chief source of opal. It often produces, also, by 
combination with the alumina and other bases at hand, 
various silicates in the cavities or fissures of the rocks, like 
the zeolites—minerals usually found in the cavities of igne- 
ous rocks. 


Opal. 


Compact and amorphous, texture colloid; also in reni- 
form and stalactitic shapes; also earthy. ’ Colors white, 
yellow, red, brown, green, blue, and gray. ‘The finest 


260 DESCRIPTIONS OF MINERALS. 


varieties exhibit from within, when turned in the hand, 
a rich play of colors of delicate shades. Lustre waxy to 
subvitreous. H. = 5°5-6°5. G. = 1°9-2°3. 

Composition. Consists of silica, like quartz; but of silica 
in a different molecular state, the hardness and specific 
gravity being less; and it being soluble in a strong alkaline 
solution, especially if heated. Usually contains a few per 
cent. of water—amounting in some kinds to 12 per cent.; 
but the water is not generally regarded as an essential con- 
stituent. Differs from quartz also in its lustre, which is 
more waxy than chalcedony; also in the total absence of a 
crystalline texture. 





VARIETIES. 


Precious Opal. External color usually milky, but hav- 
ing within a rich play of delicate tints; a gem of rare 
- beauty. A large mass in the imperial cabinet of Vienna 
weighs seventeen ounces, and is nearly as large as a man’s 
fist, but contains numerous fissures and is not entirely dis- 
engaged from the matrix. This stone was well known to 
the ancients and highly valued by them. ‘They called it 
Paideros, or Child Beautiful as Love. The noble opal is 
found near Cashau in Hungary, and in Honduras, South 
America; also on the Faroe Islands; at Esperanza, in 
Mexico. | 

Fire Opal, Girasol. An opal with yellow and bright 
hyacinth or fire-red reflections. It comes from Mexico and 
the Faroe Islands; Washington Co., Ga. A beautiful blue 
opal occurs in Queensland, Australia. 

Common Opal, Semiopal. Has the hardness of opal, its 
waxy or resinous lustre, but no colored reflections from 
within, though sometimes a milky opalescence. The 
colors are white, gray, red, yellow, bluish, greenish to 
dark grayish-green. ‘Translucent to nearly opaque. Occurs 
with some of the silicified wood of Arizona, etc., but much 
of it retains some of the structure of the wood, and is wood- 
opal. 

Hydrophane. Opaque white or yellowish when dry, but 
translucent and opalescent after immersion in water. 

Cacholong. Opaque white, or bluish white; usually 
‘associated with chalcedony. Part so called is chalcedony ; 
other specimens contain water, and are allied to hydrophane. 
Contains also a little alumina and adheres to the tongue, 


SILICA. 261 


Hyalite, Muller’s Glass. Glassy transparent ; in small 
concretions, occasionally stalactitic. Resembles somewhat 
transparent gum-arabic. An analysis obtained Silica 92°00, 
water 6°33. 

Menilite. Brown, opaque; compact reniform; occasion- 
ally slaty. Composition, Silica 85°5, water 11°0 (Klaproth). 
In slate at Menil Montant, near Paris. 

Wood Opal. Gray, brown, or black, having the structure 
of wood, being wood petrified with hydrated silica (or opal), 
instead of quartz. 

Opal Jasper. Resembles jasper in color, due to a little 
iron; but is resinous in lustre and not so hard. 

Siliceous Sinter, Geyserite. A loose, porous siliceous 
rock, grayish to white in color; deposited around geysers, 
as those of Iceland and the Yellowstone Park, in cellular 
or compact masses, sometimes in stalactitic or cauliflower- 
like shapes. Viandite is an unusually hydrous variety, a 
leathery incrustation which crumbles on drying: from 
the Yellowstone Park. Pearl sinter, or /iorite, occurs in 
volcanic tufa in smooth and shining globular, botryoidal 
masses, having a pearly lustre. 

Float Stone. A variety of opal having a porous and fibrous 
texture, and hence so light that it will float on water. It 
occurs in concretionary or tuberose masses, which often 
have a nucleus of quartz. 

Tripolite (Diatomite, Infusorial Earth). A white or 
grayish-white earth, massive, laminated, or slaty, made 
mainly of siliceous secretions of microscopic plants called 
Diatoms, with more or less of the spicules of sponges. 
Forms beds of considerable extent, and often occurs beneath 
peat (because diatoms lived in the waters of the shallow 
eas before it became a drying marsh); as in Maine, New 

ampshire, Nevada, California. It is sold as a polishing 
powder under the name of electrosilicon. Dynamite was 
formerly made by mixing nitroglycerine (liquid) with it, 
but woodpulp is now used instead. It is used for making 
solutions of soluble silica (soda silicate), for purposes of a 
cement. Owing to its poor conduction of heat, it has been 
applied as a protection to steam boilers and pipes. 

Tabasheer is a siliceous aggregation found in the joints 
of the bamboo in India, and not properly a mineral. Con- 
tains several per cent. of water, and has nearly the appear- 
ance of hyalite. 


262 DESCRIPTIONS OF MINERALS. 


Diff. Infusibility before the blowpipe is the best charac- 
ter for distinguishing opal from pitchstone, pearlstone, and 
other species it resembles. ‘The absence of anything like 
cleavage or crystalline structure is another characteristic. 
Its inferior hardness, specific gravity, and resinous or greasy 
lustre, separate it from quartz. 


Tridymite. Pure silica, like quartz and opal, with very nearly the 
hardness and specific gravity of opal, but occurring in tabular hexag- 
onal prisms, 1 A 1 = 127° 35’ overa pyr- 
amidal edge and 124° 3’ over. If not 
“) crystallized opal, it is a thérd state of 
| SiO. In trachytic and some other vol- 
canic rocks in Germany; island Vul- 
cano; Mexico; Yellowstone Park; Col- 
orado, ete. -Asmanite is the same from meteorites. 

Jenzschite. Silica, SiO:, in, it is supposed, a fourth state, it resem- 
bling opal in aspect and in solubility in alkaline solutions, but having 
the specific gravity of quartz, or 2°6. Hiittenberg, Carinthia; near 
Weissig ; Regensberg; Brazil. 

Melanophlogite. Colorless cubes (pseudomorphs ?) consisting of 
silica, with a little sulphur trioxide and water. On Sulphur, Sicily. 

Proidonite. Silicon fluoride. Observed as an exhalation at 
Vesuvius in 1872. Hieratite; 2KF -+ SiF,, Vulcano. 





2. SILICATES. 


The Silicates are here divided into the Anhydrous and the 
Hydrous. 

In part of the Anhydrous Silicates, the combining value 
or quantivalence (see page 88) of the silicon is to that of 
the basic elements as 2 to 1; in another part, as 1 to 1; 
and in a third division, as less-than-1 to 1. On this ground 
the mineral silicates are here arranged in three groups, 
named respectively: I. BistnicatEs; Il. UNISILICATEs ; 
and III. SuBSILICATES. 

In the Bisilicates, one molecule of silicon is combined 
with one molecule of an element in the protoxide state, as 
Mg, Ca, Fe, etc., or one third of a molecule of an element 
in the sesquioxide state, as Al, Fe, Mn, etc.; or, what is 
the same thing, 3 molecules of silicon, with 3 of an element 
in the protoxide state, or 1 of an element in the sesquioxide 
state. The general formulas of such compounds is hence 
RO,Si, or BO,Si,, or, if elements in both the protoxide and 
sesquioxide state are present, (R,R)O,Si,, as explained on 
page 91. 


BISILICATES. 263 


In the Unisilicates, one molecule of silicon is combined 
with two of an element in the protoxide state, that is, for 
example, Mg,, Ca,, Ie,; or with two thirds of a molecule in 
the sesquioxide state, that is, two thirds of Al, Fe, Mn. 
The formula of these silicates is hence R,O,Si, or RZ0,8i, 
or, in order to remove the fraction in the last, R,0,,8i,; 
which becomes, when elements in the protoxide and ses- 
quioxide state are both present, (R,, R),O,,Si,. 

Among the species referred to the Unisilicates there are 
some that vary from the unisilicate ratio, This occurs 
especially in species in which an alkali is present, as in the 
Feldspars, Micas, and Scapolites. | 

The Subdsilicates vary in the proportion of the silicon to 
the basic elements, and graduate into the Unisilicates. 

The same three grand divisions exist more or less satis- 
factorily among the Hydrous Silicates. 

Some hydrous silicates give evidence, by holding to the 
water when highly heated, that the water is basic (that is, 
its hydrogen replaces the metal of other oxides among the 
bases); and these, therefore, are here arranged with the 
anhydrous species. Some examplesare epidote, zoisite, and 
euclase. 

Specimens of the anhydrous silicates often contain 2 or 
3p. c. of water as a consequence of incipient alteration, 


A. ANHYDROUS SILICATES, 


I. BISILICATES. 


The bisilicates, when the base is in the protoxide state 
and have hence the general formula RO,Si, are resolved in 
analyses into protoxides and silica in the ratio of iRO to 
18i0,, in which, as the term disilicate implies, the oxygen 
of the silica is twice that of the protoxides. If the base is 
in both the protoxide and sesquioxide states, giving the for- 
mula (R,, BR) O,Si,, the mineral is resolved in analyses into 
protoxides, sesquioxides, and silica. If the ratio of the pro- 
toxides to sesquioxides is 1; 1, the formula will become 
$R,3R0,8i, which, doubled, to clear it of the fractions, 
becomes R,RO,,Si,; and analyses give then for the oxides 
and silica 3RO, 1R0,, 65S10,. 


264 DESCRIPTIONS OF MINERALS. 


Among the following Bisilicates the species from ensta- 
tite to spodumene and amphibole make a natural group 
called the hornblende, or hornblende and pyroxene group. 
They are closely related in composition and also in crystal- 
lization. 'The cleavage prism is rhombic, and has either an 
angle of about 1243° or of about 87°; and the former of 
these two rhombic prisms has just twice the breadth of the 
other; that is, if the lateral axis from the front to the back 
edge in each be taken as unity, the other lateral axis is twice 
as long in the prism of 1245° as it is in that of 87° 5’. 
The forms are either orthorhombic, monoclinic, or triclinic; 
and yet close relations in angles, as just stated, exist be- 
tween them. LEnstatite is a magnesium or magnesium and 
iron species; wollastonite, a calcium species; rhodonite, a 
manganese species; pyroxene and hornblende contain cal- 
cium with magnesium or iron; spodumene contains lithium 
and aluminium, aluminium replacing elements that in 
other species are in the protoxide state. 


Enstatite.—Bronzite. 


Orthorhombic; ZA J= 88° 16’. Prismatic cleavage 
easy. Usually possesses a fibrous appearance on the cleay- 
age surface. Also massive and lamellar. 

Color, grayish, yellowish or greenish white, or brown. 
Lustre pearly ; often metalloidal in the bronzite variety. 
H. 55. G. 3°1-3°3. 

Composition. MgO,Si = Silica 60, magnesia 40. B.B. 
infusible, and insoluble. Bronzite has a portion of the 
magnesium replaced by iron. 

Diff. Resembles amphibole and pyroxene, but is infusi- 
ble, and orthorhombic in crystallization. 

Obs. Occurs in the Vosges; Moravia; Bavaria; Baste, 
in the Hartz; Brewster’s, N. Y.; Leiperville, Texas, Mar- 
ple, Radnor’s, Pa.; Bare Hills, Md. 


Hypersthene. Near bronzite in form and composition, but contains 
a larger percentage of iron and B.B. fuses; on charcoal, becomes 
magnetic. St. Paul’s Island, in Labrador; Isle of Skye; Greenland; 
Norway, etc. Szaboite is hypersthene; Amblystegite contains still 
more iron; Diaclasite is near bronzite. 


BISILICATES. 265 


Wollastonite.—Tabular Spar. 


Monoclinic; J A J = 87° 28’, C= 69° 48’. Rarely in 
oblique flattened prisms; usually massive. Cleaves easily 
in one direction, affording a lined or indistinctly columnar 
surface. Usually white, but sometimes tinged with yellow, 
red, or brown. ‘Translucent, or rarely subtransparent. 
Lustre vitreous, pearly. Brittle. H.=4:5-5. G. = 2°85- 

2°91. 

Composition. CaQ,Si = Silica 52, lime 48 = 100. B.B. 

‘fuses with difficulty to a subtransparent, colorless glass; in 
powder decomposed by hydrochloric acid, and the solution 
gelatinizes on evaporation; often effervesces when treated 
with acid on account of the presence of calcite. 

Diff. Differs from asbestus and tremolite in its more vit- 
reous appearance and fracture, and by its gelatinizing in 
acid; from the zeolites by the absence of water, which all 
zeolites give in a closed tube; from feldspar in the fibrous 
appearance of a cleavage surface and the action of acids. 

Obs. Usually found in granite or granular limestone; 
occasionally in basalt or lava. Occurs in Ireland at Dun- 
‘more Head; at Vesuvius and Capo di Bove; in the Hartz; 
Hungary; Sweden; Finland; Norway. 

At Willsboro’, Lewis, Diana, and Roger’s Rock, N. Y., 
of a white color, along with garnet; at Boonville, in bowl- 
‘ders with garnet and pyroxene; Grenville, Canada; in 
Bucks Co., Pa.; at Keweenaw Point, L. Superior, £del- 
forsite is impure wollastonite, 


Pyroxene.—Auzgite, 


Monoclinic. “7A, T= 87° 5’, C= %38° 59’ = O A 1-1. 
Cleavage perfect parallel with the sides of this prism, and 
often distinct parallel with the i 9, 3, 
diagonals. Usually in thick _ 
and stout prisms, of 4,6, or8 7 
sides, terminating in two faces 
meeting at anedge. JA t-1 = 
igo. 3a, J A 2-4 = 136° 27’; 
-1A-1 =131° 24’, Often twin- 
ned parallel to 7-7 ; also often lamellar parallel to O, owing 
to the interposition of twinning lamelle. Massive varieties 





266 DESCRIPTIONS OF MINERALS, 


of a coarse lamellar structure; also fibrous, fibres often very 
fine and often long capillary. Also granular; usually coarse 
granular and friable; grains usually angular, sometimes 
round. Also compact massive. . 

Colors green of various shades, verging to white on one 
side and brown and black on the other, passing through 
blue shades, but not yellow. Lustre vitreous, inclining to 
resinous or pearly; the latter in fibrous varieties. ‘Trans- 
parent toopaque. H.= 5-6. G. =3°2-3°5. 

Composition. RO,Si (or RO + 8i0,); in which R may 
be Ca, Mg, Fe, Mn, and sometimes Zn, K,, Na,, these 
bases replacing one another without changing the crystal- 
line form, of which two or more are usually present ; the 
first three are most common. Calcium is always present. 
The following is an analysis of a typical variety: Silica 55:0, 
lime 23°5, magnesia 16°5, manganese protoxide ‘5, iron pro- 
toxide 455 = 100. Fuses B.B., but the fusibility varies 
with the composition, and the ferriferous varieties are most 
fusible. Insoluble in acids. } 

Diff. The crystalline form, and ready cleavage in two 
planes nearly at right angles to one another (87° 5’), are 
the best characters for its determination. 

VARIETIES.—The varieties may be divided into three sec- 
tions—the light colored, the dark colored, and the thin 
foliated. 

I. Malacolite or white augite, a calclum-magnesium py- 
roxene, including white or grayish white crystals or crystal- 
line masses. Diopside, of the same composition, in green- 
ish white or grayish green crystals, and cleavable masses 
cleaving with a bright smooth surface. Sahiite, containing 
iron in addition, and of a more dingy green color, with less 
lustre and a coarser structure than diopside, but otherwise 
similar; named from the place Sala, where it occurs. 
Fassaite, containing a little alumina in addition to the ele- 
ments of sahlite, and found in crystals of rich green shades 
and smooth and lustrous exterior; named from the foreign 
locality, Fassa. Coccolite, coarsely granular, named from 
the Greek coccos, grain ; when green, called green coccolite ; 
white, white coccolite. The specific gravity of these varie- 
ties varies from 3°25 to 3:3. 

Asbestus. Includes fibrous varieties of both pyroxene 
and hornblende; it is more particularly noticed beyond, 
under the latter species, as pyroxene is rarely asbestiform. 


BISILICATES. 267 


II. Azgite. Theblackand greenish black crystals, which 
contain a larger percentage of iron, or iron and magnesium, 
and which mostly present the form in figure 1. Specific 
gravity 3°3-3'4. ‘This is the common pyroxene of eruptive 
rocks. Hedenbergite, an iron-calcium pyroxene, a greenish 
black opaque variety, in cleavable masses affording a green- 
ish brown streak; specific gravity 3°5. dMJanganhedenberg- 
ite, near the last, contains 6 to 7 p. c. of manganese pro- 
toxide; G. = 3°55. Polylite, Hudsonite, and Jeffersonite 
fall here; the last containssome zinc oxide. ‘These varieties 
fuse more easily than the preceding, and the globule ob- 
tained is colored black by the iron oxide. 

Ill. Diallage, a thin-foliated variety, often occurring im- 
bedded in serpentine and some other rocks. Differs from 
bronzite and hypersthene in crystallization, and in being 
more fusible; the foliation is often a result of incipient 
alteration, p. 450. 

Obs. Pyroxene is one of the most common minerals. It 
is a constituent in almost all basic eruptive rocks, like basalt, 
and is frequently met with in rocks of other kinds; a white 
kind is common in granular limestone, and also a green. 
In basalt or lavas the crystals are generally small and 
black or greenish black. In other rocks it occurs of all 
the shades of color given, and the crystals of all sizes to a 
foot or more in length. One crystal from Orange County, 
measured 6 inches in length, and 10 in circumference. 
White crystals occur at Canaan, Ct.; Sheffield, Monterey, 
Mass.; Kingsbridge, New York County, and the Sing Sing 
quarries, Westchester Co., N. Y.; in Orange Co. at several 
localities; green crystals at Trumbull, Ct., at various places 
in Orange Co., N. Y., Roger’s Rock and other localities in 
Essex, Lewis, and St. Lawrence Cos. Dark green or black 
crystals are met with near Edenville, N. Y., Diana, Lewis 
Co. Large crystals occur with the apatite of Renfrew, 
Canada. Jeffersonite occurs at Franklin, in N. J. Green 
coccolite is found at Roger’s Rock, Long Pond, and Wills- 
boro’, N. Y.; black coccolite, in the forest of Dean, Orange 
Co., N. Y. Diopside, at Raymond and Rumford, Me.; 
Hustis’s farm, Phillipstown, and De Kalb, N. Y.; Fort 
Defiance, Ariz.; Gallup, N. Mex. 

Pyroxene was thus named by Haiiy from the Greek pur, 
fire, and zenos, stranger, in allusion to its occurring in 


268 DESCRIPTIONS OF MINERALS. 


lavas, where Haiiy thought it did not belong, or was a guest. 
The name Augite is from the Greek auge, lustre. 


Afgirite. Black to greenish black in color. A pyroxene contain- 
ing nearly 10 per cent. of soda, and much iron sesquioxide. Near 
Brevig in Norway ; Hot Springs, Arkansas. 

Acmite. In long highly-polished prisms, of a dark brown or red- 
dish brown color, with a pointed extremity. JA J = 86° 56’, resem- 
bling pyroxene ; contains over 12 per cent. of soda; B.B fuses easily. 
In granite, near Kongsberg, Norway; in nepheline rock near 
Montreal. 

Babingtonite. Resembles some varicties of pyroxene; crystals 
‘greenish black, splendent. In quartz, Arendal, Norway. 

Uralite. Has the form of pyroxene but cleavage of hornblende ; 
and has been produced through the alteration of pyroxene to horn- 
blende. Some Archean and igneous rocks that are now hornblendic 
were originally pyroxene rocks. 


Rhodonite.—Manganese Spar, Fowlerite. 


Triclinic, but nearly isomorphous with pyroxene. Also 
massive. 
Color reddish, commonly deep flesh-red; also brownish, 
greenish, or yellowish, when impure; very often black on 
the surface; streak uncolored. Lustre vitreous. Transpa- 
rent to opaque. Becomes black on exposure. H. = 5*5- 

tii Cae fe tae 

Composition. MnO,Si = Silica 45-9, manganese protox- 
ide 54:1=100. It commonly contains a little iron and 
lime replacing the manganese. Becomes dark brown when 
heated; with borax in the outer flame, gives a deep violet 
color to the bead while hot, a red-brown when cold. A va- 
riety containing a little zinc, from Franklin Furnace, N. J., 
has been named Meatingine. 

Diff. Resembles somewhat a flesh-red feldspar, but differs 
in greater specific gravity, in blackening on exposure, and 
in the glass with borax. 

Obs. Occurs in Sweden, the Hartz, Siberia, and else- 
where. In the United States it is found at Blue Hill Bay, 
Me.; Plainfield and Cummington, Mass.; abundantly at 
Hinsdale, and on Stony Mountain, near Winchester, N. H.; 
in crystals at Franklin Furnace, N. J.; at Alice Mine, 
Butte City, Montana, The black exterior is a more or less 
pure hydrated oxide of manganese, produced by oxidation. 
A hydrous rhodonite has been called Hydro-rhodonite. 

Rhodonite may be used in making a violet-colored glass, 


BISILICATES. 269 


and also for a colored glazing on stoneware. It receives a 
high polish and is sometimes employed for inlaid work. 


Spodumene. 


Monoclinic. JA IT=87°, C= 69° 40’, being near pyrox- 
ene. Cleavage easy, parallel to Z and 7-7. Surface of 
cleavage pearly. Color grayish or greenish; pale amethys- 
tine; rarely emerald-green. Lustre of cleavage surface 
pearly. Translucent to subtranslucent. H.= 65-7. G. 
= 3°15-3°19. 

Composition. (R,,-Al)O,Si,, in which R equals Li,, and 
3Li, is to Al as 1:3; this corresponds to Li,AlO,,Si, = 
Silica 64°9, alumina 27°6, lithia 7°5 — 100. B.B. becomes 
white and opaque, fuses, swells up, and imparts to the flame 
the purple-red flame of lithia. Unaffected by acids. 

Diff. Resembles feldspar and scapolite, but has a higher 
specific gravity and a more pearly lustre, and affords rhom- 
bic prisms by easy cleavage. ‘The lithia reaction is its 
most characteristic test. 

Obs. Occurs in granite at Goshen, Chesterfield, Norwich, 
and Sterling, Mass.; at Windham, Me.; at Brookfield and 
Branchville, Ot.; at Stony Point, Alexander Co., N. C., 
an emerald-green variety (Hiddenite) rivalling the emerald 
as a gem; 2 m. from Harney, Black Hills, Dak.; at Uts, 
in Sweden; Sterzing in the Tyrol; and at Killiney Bay, 
near Dublin. Some crystals from Branchville, Goshen, and 
the Black Hillsa yard ormorelong. Cymatolite (a mixture 
of albite and muscovite), Avllinite, muscovite, albite, micro- 
cline, eucryptite, are among the results of its alteration at 
Branchyille, 

This mineral is remarkable for the Withia it contains. 


Petalite. 


Monoclinic. In imperfectly cleavable masses; most 
prominent cleavage angle 141° 30’. Color white, gray, 
pale reddish, greenish. Lustre vitreous to sub-pearly. 
Translucent. H,. = 6-6°5. G. = 2°5. 

Composition. Contains lithia, like spodumene, and 
affords Silica 77:9, alumina 17°7, lithia 3:1, soda 1°3 = 100. 
Phosphoresces when gently heated. IT'uses with difficulty 
on the edges. Reacts for lithia. | 


ag DESCRIPTIONS OF MINERALS. 


Di if. Like spodumene in the lithia reaction, but unlike 
it in lustre, specific gravity, and greater fusibility. 

Obs. From Uté, Sweden; also from Elba (Castor or Cas- 
torite). An alteration product of castor has been called 
Hydrocastorite. 


Amphibole.—Hornblende. 


Monoclinic; JA [= 124° 30, C= 75° 2’. Cleavage per- 
fect parallel with J. Often in long, 
slender, flat rhombic prisms (Fig. 2), 
breaking easily transversely; also often 
in 6-sided prisms, with oblique extremi- 
ties. Frequently columnar, with a bladed 
structure; long fibrous or asbestiform, the 
fibres coarse or fine, often like flax, and 
pearly or silky; also lamellar; also granu- 
lar, either coarse or fine. 

Colors white to black, passing through 
bluish green, grayish green, green, and 
brownish green shades, to black. Lustre vitreous, with 
the cleavage face inclining to pearly; fibrous varieties silky. 
Nearly transparent to opaque. H.=5-6. G. = 2°9-3°4, 

Composition. RO,Si (or RO-+ $i0,), as for pyroxene. 
R may correspond to ‘two or more of the basic elements Mg, 
Ca, Fe, Mn, Na,, K,, the first three being most common. 
Aluminium often replaces a portion of the silicon. B.B. as 
in pyroxene; fuses, but the fusibility varies indefinitely, 
being easiest in the black varieties. 

Diff. Distinguished from pyroxene by the very ready . 
cleavages parallel to a prism of 1244°, and the prevalence 
of 6-sided prisms or sharp rhombic instead of 87° 5’. 

This species, like pyroxene, has numerous varieties, dif- 
fering much in external appearance, and arising from the 
same causes—isomorphism, and crystallization. ‘The fol- 
lowing are the most important : 





I. LIGHT-COLORED VARIETIES. 


Tremolite, Grammatite. White and grayish, in bladed 
crystallizations and long crystals penetrating the gangue 
or aggregated into coarse columnar forms. Sometimes 
nearly transparent. G.=2°9. Formula (Ca, Mg)O,Si = 


BISILICATES. Q71 


Silica 57°70, magnesia 28°85, lime 13°45 = 100. Named 
from Tremola, in Switzerland, where it is not found. 

Actinolite. Light green fibrous, columnar and prismatic, 
and massive; amagnesium-calcium-ironamphibole. Glassy 
actinolite includes the bright glassy, green crystals, usually 
long and slender, and penetrating the gangue like tremo- 
lite; radiated, olive-green masses, consisting of aggrega- 
tions of coarse acicular fibres, radiating or divergent; asbes- 
ee resembles the radiated, but the fibres more delicate; 

.= 3°0-3'1. Named actinolite from the Greek, aktin, a 
ray of the sun, referring to the frequent radiated structure. 

Composition of glassy actinolite: Silica 59°75, magnesia 
21°1, lime 14°25, iron protoxide 3:9, manganese protoxide 
0°3, hydrofluoric acid 0°8 (Bonsdorf). 

Asbestus. In slender fibres easily separable, and some- 
times like flax. Hither green or white. Amianthus in- 
cludes fine silky varieties. (Much so called is serpentine; 
serpentine is hydrous, and is thereby easily distinguished.) 
Ligniform asbestus is compact and hard, brownish and 
yellowish in color, looking like petrified wood. Mountain 
leather occurs in thin, tough sheets, feeling a little like kid 
leather; consists of interlaced fibres of asbestus, and forms 
thin seams between layers or in fissures of rocks. Mountain 
cork is similar, but is in thicker masses; it has the elasticity 
of cork, and is usually white or grayish white. Bretslakite 
is a wool-like variety from Vesuvius. 

The preceding light-colored varieties contain little or no 
alumina or iron. 

Nephrite. A tough compact variety, related to tremolite. 
Color light green or blue. Breaks with a splintery fracture 
and glistening lustre. H. = 6-6°5. G.=3. A magne- 
sium-calecium amphibole. Nephrite is made into images, 
and was formerly worn asa charm. It was supposed to be 
a cure for diseases of the kidney, whence the name, from 
the Greek, nephros, kidney. In New Zealand, China, and 
Western America it is carved by the inhabitants, or pol- 
lished down into various fanciful shapes. It is called jade; 
but the aluminium-sodium silicate, called jadeite, is the 
stone most highly prized of all that pass under the name 
of jade. Part of the ‘‘ jade” of China is prehnite. 


272 DESCRIPTIONS OF MINERALS, 


II, DARK-COLORED VARIETIES 


Cummingtonite. A magnesium-iron amphibole; color 
gray or brown; usually fibrous. Named from the locality 
where found, Cummington, Mass. 

Pargasite. Dark green crystals, short and stout (resem- 
bling Fig. 4), with bright lustre, of which Pargasin Finland — 
is a noted locality. G. =3°'11. Composition: Silica 45:5, 
alumina 14:9, iron protoxide 8°8, manganese protoxide 1°5, 
magnesia 14°4, lime 14°9 = 100. 

Hornblende. Black and greenish black erystals and mas- 
Sive specimens. Often in slender crystallizations like 
actinolite; also short and stout like Figs. 4 and 5, the latter 
more especially. Contains a large percentage of iron oxide, 
and to this owes its dark color. A tough mineral especially 
when massive, as is implied in the nameit bears. Pargasite 
and hornblende contain both alumina and iron. Compost- 
tion: Silica 48°8, alumina 7°5, magnesia 13°6, lime 10°2, 
iron protoxide 18 8, manganese protoxide 1:1 = 100. 

Bergamaskite. A variety containing nomagnesia. From 
Bergamo. 

Obs. An essential constituent of certain rocks, as syenyte, 
dioryte, and hornblende schist. Actinolite is usually found 
in magnesian rocks, as tale, steatite or serpentine; tremo- 
lite in crystalline dolomite; asbestus in the above rocks and 
also in serpentine. The pyroxene of some Archean and 
igneous rocks has been found to be often changed through- 
out to hornblende (uralite). The two species differ in 
crystallization, and not in composition; and pyroxene is the 
less stable form of the two. See p. : 

Black crystals of hornblende occur at Franconia, N. H., 
Chester, Mass.; Thomastown, Me.; Willsboro’, N. Y.; 
Orange Co., N. Y.; and elsewhere. Pargasite, at Phipps- 
burg and Parsonsfield, Me.; glassy actinolite, in steatite or 
tale, at Windham, Readsboro’, and New Fane, Vt.; Middle- 
field and Blanford, Mass.; and radiated varieties at the 
same localities and many others. Tremolite and gray 
hornblende occur at Canaan, Ct.; Sheffield, Lee, Monterey, 
Mass.; Thomaston and Raymond, Me.; Dover, Kings- 
bridge, and New York Island, N. Y.; at Chestnut Hill, 
Pa.; at the Bare Hills, Md. Asbestus at many of the above 
localities; also Brighton and Sheffield, Mass.; Cotton Rock 


BISILICATES, — 243 


and Hustis’s farm, Phillipstown, N. Y.; Rabun and Fulton 
Cos., Ga. (where it is mined); Western N. Carolina; San 
Bernardino and San Diego and Calaveras Cos., Cal.; 
Province of Quebec, Canada (where it is mined, and is of 
excellent quality). Mountain leather is met with at 
Brunswick, N. J. Hdenite,a white aluminous kind, occurs 
at Kdenville, N. Y. 

Asbestus is the only variety of this species used in the 
arts. The flax-like variety is sometimes woven into fire- 
proof textures. Its incombustibility and slow conduction 
of heat render it a complete protection against the flames. 
It is often made into gloves. A fabric when dirty need 
only be thrown into the fire for a few minutes to be white 
again. The ancients, who were acquainted with its prop- 
erties, are said to have used it for napkins, on account of 
the ease with which it was cleaned. It was also the wick of 
the lamps in the ancient temples; and because it maintained 
a perpetual flame without being consumed, they named it 
asbestos, unconsumed. It is now used for the same pur- 
pose by the natives of Greenland. The name amianthus 
alludes to the ease of cleaning it, and is derived from 
amiantos, undefiled. Asbestus is extensively used for lin- 
ing iron safes, and for protecting steam pipes and boilers. 
About 1600 tons of asbestus were used in the U. States in 
‘1882; the average price $30 per ton. The Canadian is the 
best, and brings $25 to $90 to the ton. It is obtained also 
in Italy and Australia. The most of that used is serpen- 
tine. 7 


Anthophyllite. Related in the angle of its prism to hornblende, but 
orthorhombic; in composition, and infusibility B.B., near bronzite ; 
B.B. becomes magnetic. Kongsberg, Modum, Norway. Silfbergite 
is a manganesian variety of anthophyllite. 

Kunfferite has the hornblende angle, but in composition is like 
enstatite, being a magnesian silicate. 

Arfvedsonite. Near hornblende; but contains over 10 per cent. of 
soda, like acmite. Greenland; Norway; El Paso, Col. 

Crocidolite. Near arfvedsonite in composition; lavender-blue to 
leek-green; fibrous. Orange River, South Africa; the Vosges; 
Rhode Island. Silicified crocidolite containing some limonite, now 
common in polished specimens, is called tiger stone. 

Glaucophane. A bluish mineral with the amphibole angle. Island 
of Syra; Zermatt; N. Caledonia. Wichiis?te may be the same 
species. Gastaldite is a related mineral from Aosta. 

Milariie. Hexagonal; composition (KH)Ca,A1032Si,.; being a qua- 
tersilicate instead of a bisilicate. Val Giuf, Graubiinden (Grisons), 


18 


274 DESCRIPTIONS OF MINERALS. 


Beryl.—Emerald. 


Hexagonal. In hexagonal prisms; O on 1 (plane on edge 
O:I)=150° 3’. Cleavage basal, not very 
distinct. Rarely massive. 

Color green, pale blue and yellow, emerald- 
I} y | z| green. Streak uncolored. Lustre vitreous; 
| sometimes resinous. ‘Transparent to sub- 
translucent. Brittle H.= 75-8 G.= 

2°67-2°75. 

VARIETIES. The emerald is the rich green variety ; it 
owes its color to the presence of chromium. Seryl includes 
the paler varieties, which are colored by iron. Aquamarine. 
includes clear beryls of a sea-green, pale-bluish or bluish- 
green tint. (Golden emerald has a rich yellow color. 

Composition. BeAl,O,,Si, with basic hydrogen in place 
of a sixth atomically of the beryllium. ‘The beryl of Hebron 
afforded Silica 62°10, alumina 18°92, beryllium oxide 16°35, 
iron protoxide 0°47, cesium oxide 2°93, soda 1°82, lithia 
1:17, lime 0°35, water 2°33 =100°45. Other varieties fail of 
cesium and lithium. Hmerald contains less than one per 
cent. of chromium oxide. B.B. becomes clouded, but does 
not fuse; at a very high temperature the edges are rounded. 
Unacted upon by acids. Rosterite is a variety from Elba. 
Pseudo-smaragdite is altered beryl. 

Diff. The hardness distinguishes this species from apa- 
tite; and this character, and also the form of the crystals, 
from green tourmaline. ; 

Obs. Found in granite, gneiss, mica schist. Fine emer- 
alds occur at Muso, near Santa Fé, in New Granada, in 
dolomite; one crystal, 24 in. long and about 2 in diameter, 
is in the cabinet of the Duke of Devonshire; another more 
splendid specimen, weighing only 6 oz., formerly in the 
possession of Mr. Hope, of London, cost £500. Emeralds 
of less beauty and great size occur in Siberia; one in the 
royal collection of Russia is 4$ inches in length and 
12 in breadth, and weighs 16% pounds troy; another is 7 
inches long and 4 broad, and weighs 6 pounds. Mount 
Zalora in Upper Egypt affords a less distinct variety. Some 
fine emeralds have been obtained at the Stony Point Mine, 
in Alexander Co., N. C.; one crystal was nearly 10 in, 
long. 


UNISILICATES, page), 


The finest beryls (aguamarines) come from Siberia, Hin- 
dostan, and Brazil. One specimen belonging to Dom Pedro 
is as large as the head of a calf, and weighs 225 ounces, or 
more than 184 pounds troy; it is transparent and without a 
flaw. In 1827 a fine aquamarine, weighing 35 grams, was 
found in Siberia, which is said to have been valued at 
600,000 francs. 

In the U. States beryls of enormous size have been ob- 
tained, but seldom transparent crystals. One hexagonal 
prism from Grafton, N. H., weighing 2900 lbs., 4 ft. long 
and 32 by 22 inches in its diameters, was of a bluish green 
color, with part of one extremity dull green and yellow. 
The finest crystals, some good for gems, have been found 
at Stoneham, Me.; also at Albany, Norway, Bethel, and 
elsewhere, Me.; fine at Royalston, Mass., formerly fine at 
Haddam, Ct.; also at Avondale mines, Delaware Co., Pa.; 
near Morgantown, and elsewhere, Burke Co., and Ray’s 
Mine, Yancey Co., and elsewhere, N.C. Other localities are 
Barre, Fitchburg, Goshen, Mass.; Wilmot, N. H.; Grafton, 
Vt.; Monroe, Portland, Ct.; Leiperville, Chester, Upper 
Providence, Middletown, Concord, Marple, Pa. 


Phenacite. A rhombohedral beryllium silicate, in colorless and 
yellowish crystals, with H. = 75-8 and G.= 38. The Urals; Switzer- 
land; Durango, Mexico; Pike’s Peak, Col., one 3 in. across; Florissant 
topaz loc. Col. 

Bertrandite is related to phenacite incomposition. It is orthorhom- 
bic, with Z A = 121° 20’; colorless or yellowish; G. = 2°59. From 
near Nantes, France. 

Hudialyte, Pale rose-red, crystals of rhombohedral form, containing 
15°6 per cent. of zirconia. From West Greenland. Hwucolite of Nor- 
way is here included. 

Polluctie. Isometric. White, with vitreous lustre, and G. = 2°868. 
A cesiwm silicate. Analysis afforded Rammelsberg Silica 48°15, alu- 
mina 16°31, potash 0°47, soda 2°48, cesium oxide 30°00, water 2°59 = 
100, giving very nearly the bisilicate formula H.Cs,A10,;Si;. Elba. 

Cappelenite. Yttrium silico-borate; hexagonal; brown; G. = 4°4, 
Norway. 


II. UNISILICATES. 


For the convenience of the student, the general formulas 
of the regular Unisilicates are here re-stated. They are as 
follows: 

If the base is in the protoxide state alone, the formula is 
R,O Si (= 2RO + 810,), in which R stands for Ca, Mg, Fe, 


276 DESCRIPTIONS OF MINERALS. 


Mn, K,, Na,, or Li,, or other mutually replaceable base. 
In analyses, “the mineral is resolved into protoxides and 
silica, in the ratio of 2RO to SiO,, in which the oxygen of 
the silica equals that of the basic portion. 

If the base is in the sesquioxide state alone, the formula 
is R,O,,8i, (=2BR0, + 38810,), in which R may stand for 
Al, Fe, or Mn, etc. Here the mineral is resolved, in analy- 
ses, into sesquioxides and silica in the ratio of 2RO, to 3810,, 
in which the oxygen of the silica again equals that of the 
basic portion. 

If the basic portion is partly in the protoxide state and 
partly in the sesquioxide, the formula, in its most general 
form, is (R,, R),0,,Si,. In this formula the ratio of R, to 
R is not stated. If the ratio is 1: 1, ie aaa becomes 
R,BRO,,Si,, or its equivalent (3R, 1R),0.,8 In a case like 
this last, the mineral is resolved, in analteae into protoxides, 
sesquioxides, and silica, in the ratio of 3RO: RO, : 38i0,, 
in which again the oxygen of the bases equals that of the 
silica. 

If the proportion of R, to 8 is 1:3, this corresponds to 
4K, : BR, or, its equivalent, R: 8; and hence the formula in 
its ‘general ‘form will be RRO,Si.. 

If the base is in the dioxide state, the formula becomes 
RO,Si (= RO, + 8i0,), an example of which occurs in zir- 
con, whose formula is ZrO,Si. 

There are several natural groups of species among the 
Unisilicates. 


GROUP. STATE OF BASES. CRYSTALLIZATION. 
1. Chrysolite group, -protoxide, Orthorhombice. 
2. Willemite group, protoxide, Hexagonal. 
9 : 
3. Garnet group, Pee and sesqui- t Isometric. 
4. Zircon BTOUDy dioxide, Tetragonal. 
5. Idocrase and Sca- protox. and _ ses- 
polite groups, quiox. Tetragonal. 
Orthorhombic ; plane 
6. Mica group, protox. and sesquiox. angle of base, 120°; 
micaceous. 


7. Feldspar group, protox. and __ ses- t Monoclinic or triclin- 
quiox. ic, JA I nearly 120°. 


In the Scapolite, Mica, and Feldspar groups part of the 
species contain an alkali metal in the basic portion, and 
such kinds have generally an excess of silica. Among the 
feldspars, the species containing only calcium as the pro-— 


UNISILICATES. ya 


toxide base is a true unisilicate. In the others, there is an 
excess directly proportional to the increase of the soda, as 
explained beyond. 


Chrysolite.—Olivine. Peridot. 


Orthorhombic. In rectangular prisms having cleavage 
parallel with 7-7. Usually in imbedded grains of an olive- 
green color, looking like green bottle-glass; also yellowish 
green. lustre vitreous. ‘Transparent to translucent. 
Bae 6-7. G;— 3°3-3'6. 

Composition. (Mg, Fe),0,Si (or 2 (Mg, Fe) O + SiO,) =, 
for a common variety, Silica 41°39, magnesia 50°90, iron 
protoxide 7-71=100. The amount of iron is variable. 
B.B. whitens but is infusible; with borax, a yellow bead 
owing to the iron present. Decomposed by hydrochloric 
acid, and the solution gelatinizes when evaporated. Hya- 
losiderite is a very ferruginous variety which fuses B.B. 

Diff. Distinguished from green quartz by its occurring 
disseminated in basaltic rocks, which never so occurs; and 
-inits cleavage. From obsidian or volcanic glass it differs 
in its infusibility. 

Obs. Occurs as a rock formation; also in a large part of 
the basalt of volcanic regions, and also in some andesyte, in 
various countries. As arock it occurs in N. Carolina and 
Pennsylvania; and as a constituent of basalt in the eruptive 
regions of the Pacific slope, and sparingly in the trap (basalt) 
of New Jersey, New Hampshire, etc. Soltonite, from lime- 
stone at Bolton, Mass., is a variety of chrysolite. It also 
occurs in many meteorites. 

Sometimes used as a gem, but too soft to be valued, and 
not delicate in its shade of color. 

Forsterite isa magnesian chrysolite Mg.0,8i; Hayalite, an iron chrys- 
olite, Fe.O,Si, and fusible, a rather common variety, occurring occa- 
sionally in crystals as in the obsidian of Yellowstone Park; Monticel- 
lite, a calcium-magnesium, CaMg,0,S8i; Hortonolite, an iron-magnesium 
manganese chrysolite from Orange Co., N. Y.; Rapperite, an iron- 
manganese-zine chrysolite from Stirling Hill, N. J.; Tephrotte, a man- 
ganese chrysolite,Mn.O,Si, from Stirling Hill, N. J.; Anebelite,a man- 
ganese-iron chrysolite, MnFeO,Si, from Dannemora. Igelstrdémite (of 
M. Weibull) is near Knebelite. Neochrysolite, from Vesuvius, contains 
some manganese. 

Cuspidite. In rose-red spear-shaped monoclinic crystals; H. = 5°6; 
G. = 2°85-2°86. Contains silica, lime, fluorine. From Vesuvius. 

Leucophanite and Meliphanite. Contain the element beryllium; the 


pve Dy DESCRIPTIONS OF MINERALS. 


former, greenish yellow, and G. = 2°97; the latter, yellow and G. = 
3°018. Norway. 

Wohlertte. Contains zirconium and also niobium; color light 
yellow; G. = 3°41. 

Willem#ie. Zinc unisilicate, Zn.O0,8i. See page 173. 

Dioptase. Copper silicate, which, making the water basic, is a uni- 
silicate, H,CuQ.,Si. See page 156. The Kirghese Steppes; Chili. 

Friedelite. Rose-red manganese silicate, of the general formula 
R,0,Si, in which R consists of manganese and hydrogen in the atomic 
ratio 2:1. The Pyrenees. 

Helvite (Helvin). Isometric; in tetrahedral crystals; color honey- 
yellow, brownish, greenish; lustre vitreo-resinous; H. = 6-6:5; G. = 
3°1-3°3; contains manganese, iron and beryllium, and some sulphur. 
Saxony; Norway; Amelia Co., Va. 

Danalite. Isometric, in octahedral crystals; color flesh-red to gray; 
lustre vitreo-resinous; H. = 5°5; G. = 3°427; contains zinc, beryllium, 
iron, manganese. Disseminated through granite at Rockport, Cape 
Ann, Mass.; near Gloucester, Mass.; Bartlett, N. H. 

Hulytite. A bismuth silicate from Johanngeorgenstadt. 

Bismutoferrite. A bismuth-iron silicate. 

Peckhamite. In nodules in an Iowa meteorite. 


Garnet. 


Isometric. Dodecahedrons (Fig. 1) and trapezohedrons 
(Fig. 2); both forms are common, and are sometimes vari- 
ously modified. Cleavage parallel to the faces of the dode- 
cahedron sometimes rather distinct. Also found massive 
granular, and coarse lamellar. 

Color deep red to cinnamon color; also brown, black, 





green, emerald-green, rarely colorless. Transparent to 
opaque. Lustre vitreous. Brittle H.=6%-7'5. G.= 
3°1-4°3. 

Composition and Varieties. General formula R,RO,,Si,; 
in which R may be calcium, magnesium, iron, manganese, 
and R may be aluminium, iron, chromium. The varieties 
owe their differences to the proportions of these elements, 
or the substitution of one for another. Most garnets fuse 
easily B.B. to a brown or black glass; but the fusibility 


UNISILICATES, 279 


varies, and chrome-garnet is infusible. Not decomposed 
by hydrochloric acid; but if first ignited, then pulverized 
and treated. with acid, they are decomposed, and the solu- 
tion usually gelatinizes when evaporated. 

There are three series among the varicties: one, that of 
alumina-garnet, in which the sesquioxide base is chiefly 
aluminium; the second, that of iron-garnet, in which the 
sesquioxide base is chiefly iron instead of aluminium; and 
third, chrome-garnet, in which it is chromium. 

J. ALUMINA-GARNET. 

Almandite (Almandine). An iron alumina-garnet, Fe, 
AlO,,Si, = Silica 36:1, alumina 20°6, iron protoxide 43°3 = 
100. G. = 3°8-4:25. Of various shades of red, ruby-red, 
hyacinth-red, columbine-red, brownish red. If transparent, 
called precious garnet; if not so, common garnet. 

Grossularite (including Cinnamon Stone, Essonite, Suc- 
cinite). A lime alumina-garnet, Ca,Al10,,Si, =Silica 40:1, 
alumina 22°7, lime 37°2 = 100, but often with some iron 
protoxide in place of part of the lime. G. =3:4-3-%5. 
Grossularite is pale green, and was hence named from the 
Latin for gooseberry. Cinnamon Stone or Hssonite is cin- 
namon-colored. Swccinite is amber-colored. 

Pyrope. A magnesia alumina-garnet Mg,A10,,Si,. 
Color deep red, but varying to black and green. G.= 3°15 
-3 8. 

Spessartite. A manganese alumina-garnet (Mn, Fe),Al 
O,,Si,, some iron replacing part of the manganese. Color 
red, brownish red, hyacinth-red. G.= mostly 4-44. A 
Haddam specimen afforded Silica 35°8, alumina 18:1, iron 
protoxide 14:9, manganese protoxide 31:0. 

II. [Ron-GARNET. 

Andradite. A lime iron-garnet, Ca,FeO,,Si,. Colors 
various, from that of almandite or common garnet, to a 
wine-yellow, as in Zopazolite; green, as in Jelletite; and 
black, as in Melanite and Pyreneite. G. = 3°644., 

Colophonite. A dark red to brownish yellow coarse gran- 
ular garnet having often iridescent hues. 

Aplome. <A red variety. 

Rothoffite. Has manganese in place of part of the lime, 
and a yellowish brown to reddish brown color. 

Ytter-garnet. Contains yttria in place of part of the 
lime. © 

Bredbergite. A lime-magnesia iron-garnet. 


280 DESCRIPTIONS OF MINERALS. 


III. CHroME-GARNET. 

Ouvarovite. An emerald-green lime chrome-garnét, Ca, 
Cr,O,,Si,, with some alumina. G. = 3°41-3°52. 

Diff. The vitreous lustre of fractured garnet, and its 
usual dodecahedral and trapezohedral forms, are easy char- 
acters for distinguishing it. 

Obs. Occurs abundantly in mica schist, hornblende schist, 
and gneiss, and somewhat less frequently in granite and 
granular limestone; sometimes in serpentine; occasionally in 
trap, and other igneous rocks. A massive buff-colored gar- 
net, occurring in thin layers, in hydromica (sericite) schist, 
in Belgium, i is the material of the finest of razor-stones. 

The best precious garnets are from Ceylon and Green- 
land; cinnamon stone comes from Ceylon and Sweden; gros- 
sularite occurs in the Wilui River, Siberia, and at Tellemar- 
ken in Norway; green garnets are found at Schwartzenberg, 
Saxony; melanite, in the Vesuvian lavas; owvarovite, at Bis- 
sersk in Russia; topazolite, at Mussa, Piedmont. 

In the U. States, fine clear red crystals occur in Delaware 
Co., Pa.; Stony Point, N.C. Crystals of a dark-red color, 
of small size at Hanover, N. H.; large, some 14 in., at 
Haverhill and Springfield, N. H.; large at New Fane, Vt.; 
at Unity, Brunswick, Streaked "Mountain, Albany, etc., 
Me., some of the Albany garnets weighing each 20 Ibs.; 3 at 
Monroe, Lyme, and Redding, Ct.; Bedford, Chesterfield, 
Barre, Brookfield, and Brimfield, Mass. ; ; very ‘large and fine 
at Russell, Mass.; Roger’s Rock, “Essex Co. . N. Y.; Frank- 
lin, N. J.; ‘Avondale, Chester, Darby, and elsewhere, Fax 
Burke, Caldwell, and Catawba Cos., N. C., especially fine 
8m. 8. EH. of Morgantown, and near Warlick, in Burke Co. ; 
large and fine in Alaska, near Ft. Wrangel. Zssonite at 
Carlisle and Boxborough, Mass.; with idocrase at Parsons- 
field, Phippsburg and Rumford, Me.; Amherst, N. H.; 
Amity, N. Y.; Franklin, Sussex Co., N. J.s Dixon’s 
Quarry, seven miles from Wilmington, Del., in fine trapezo- 
hedrons. Grossularite, Good Hope mine, Cal.; Gila Cafion, 
Arizona. Melanite, at Franklin, N. J., and Germantown, 
Pa. Ouvarovite, at Wood’s chrome-mine, Lancaster Co., 
Pa.; Orford and Wakefield, Canada. Colophonite, at Wills- 
borough and Lewis, Essex Co. .. N. Y.; N. Madison, Conn. 
Colorless at Hull, Canada. 

Garnet is the carbuncle of the ancients. The alabandic 
carbuncles of Pliny were so called because cut and polished 


UNISILICATES. 281 


at Alabanda, and hence the name Almandine now in use. 
The garnet is also supposed to have been the hyacinth of 
the ancients. 

Clear deep-red garnets make a rich gem, and are much 
used; those of Pegu are most valued. They are cut thin, 
on account of their depth of color. Cinnamon-stone is 
also employed for the same purpose. Powdered garnet is 
sometimes used as emery. Pliny describes vessels, of the 
capacity of a pint, formed from large carbuncles, “‘ devoid 
of lustre and transparency, and of a dingy color,” which 
probably were large garnets. 


Zircon. 


Tetragonal; ZA 1 = 132° 10’; 1A 1 =123°.19’. Cleay- 
age parallel to J, but imperfect. Usually in crystals; but 
also granular. 





Color brownish red, brown, and red, of clear tints; also 
yellow, gray, and white. Streak uncolored. Lustre more 
or lessadamantine. Often transparent; also nearly opaque. 
Fracture conchoidal, brilliant. H.= 7:5. G. of purest 
crystals = 4°6-4°86, but varies from 4—4°9. 

Composition. ZrO,Si (= 2ZrO + 8i0,) = Silica 33, zir- 
conia 67 = 100. B.B. infusible, but loses color. 

VARIETIES. Transparent red specimens are called hya- 
ciuths; colorless, from Ceylon, having a smoky tinge, ja7- 
gon (sold for inferior diamonds, which they resemble, 
though much less hard). Gray and brownish varieties 
sometimes called zirconite. 

Diff. Readily distinguished from species which it resem- 
bles by its crystals, specific gravity, and adamantine lustre. 

Obs. Confined to crystalline rocks, occurring. in granite, 
granulyte, gneiss, granular limestone, and some igneous 
rocks. Zircon-syenyte is an elexolite-syenyte with dissemi- 
nated zircons. Crystals often occur in auriferous sands. 
Hyacinth occurs mostly in grains in such sands, and comes 
from Ceylon; Auvergne, Bohemia, and elsewhere in Hurope. 


282 DESCRIPTIONS OF MINERALS. 


Siberia affords large zircons. Fine specimens come from 
Greenland. eccarite is an olive-green var. from Ceylon. 

In the United States, gray crystals occur in Buncombe 
Co., N. C.; and common in the gold sands of Polk, Mc- 
Dowell, Rutherford, and other cos., N. C.; cinnamon-red 
in Moriah, Essex Co., Two Ponds and elsewhere, Orange 
Go., Hammond, St. Lawrence Co., and Johnsbury, Warren 
Co., N. Y.; Franklin, N. J.; Litchfield, Me.; Middlebury 
Vt.; fine near the Pike’s Peak toll-road, due west of the 
Cheyenne Mts.; also elsewhere in the Pike’s Peak region. 
Canada, at Grenville, etc., also in Renfrew Co., one crystal 
reported nearly 10 in. long and 4 in. through, weighing 12 
pounds. 

Named hyacinth from the Greek huakinthos; but it is 

doubtful whether the ancients so called stones of the zircon 
species. 
The clear crystals (hyacinths) are of common use in 
jewelry. When heated in a crucible with lime, they lose 
their color, and resemble a pale straw-yellow diamond, for 
which they are substituted. Zircon is also used in jewelling 
watches. The hyacinth of commerce is to a great extent 
cinnamon-stone, a variety of garnet. The earth zirconia 
is used as an advantageous substitute for lime in the oxyhy- 
drogen lantern. 

Auerbachite, Malacon, Tachyaphaltite, Girstedite, Bragite, are names 
of zircon-like minerals supposed to be zircon partly altered. Alvite is 
similar in form to zircon. Heldburgite is probably near zircon. 

Loventte. Zirconium-calcium-sodium silicate; monoclinic; brown, 
yellowish. Norway. 


The earth zirconia is also found in the rare minerals ewddalyte and 
wohlerite; also in polymignite, eschynite; also sparingly in fergusonite. 


Vesuvianite.—Idocrase. 
Tetragonal. OA 1= 142° 46’; 1 A 1= 129° 21’, 1:12 
3. 4, 





1 


= 127° 14’. Cleavage not very distinct parallel with J. 
Also massive granular, and subcolumnar. 


UNISILICATES, 283 


Color brown; sometimes passing into green. Some va- 
rieties oil-green in the direction of the axis and yellowish 
green transverse to it. Streak uncolored. Lustre vit- 
reous. Subtransparent to nearly opaque. H.=6%5. G. = 
3°33-3°4, 

Composition. (4Ca,2Al),0,,51,. A small part of the Ca 
isusually replaced by magnesium, and part of the aluminium 
sometimes by iron in the sesquioxide state. Percentage of 
a common variety, Silica 37:3, alumina 16:1, iron sesquiox- 
ide 3°7, lime 35°4, magnesia 2°1, iron protoxide 2°9, water 
2°1=99°6. B.B. fuses easily with effervescence to a green- 
ish or brownish globule. 

Diff. Resembles some brown garnet, tourmaline and 
epidote, but differs in crystallization, and in greater fusi- 
bility. 

Obs. First found in the lavas of Vesuvius, and hence the 
name. Occurs in Piedmont; near Christiania, Norway; in 
Siberia; in the Fassa Valley. Cyprine includes blue crys- 
tals from Tellemarken, Norway; supposed to be colored by 
copper. 

In the U. States, in fine crystals at Phippsburg and Rum- 
ford, Sandford, Parsonsfield and Poland, Me.; Newton, 
N. J.; Amity, N. Y.; inCanada at Calumet Falls, and at 
Grenville. 

Named from the Greek edo, to see, and krasis, mixture; 
because its crystalline forms have much resemblance to 
those of some other species. 

' Sometimes cut as a gem for rings. 

Mellilite in honey-yellow crystals (which includes Hum- 
boldtilite), is a related tetragonai species, from Capo di Bove, 
near Rome and Mount Somma, Vesuvius. 


Epidote. 

Monoclinic; C = 89° 27’; i-¢ A 1-4 = 115° 24’, 7-7 A —1-¢ 
= 116°18’, —1 A —1=109°33’. 
Cleavage parallel to 7-7; less dis- 
tinct parallel to 1-7. Also mas- SST Dy, 
Sive granular and forming rock 
masses; sometimes columnar or 
fibrous. 

Color yellowish green (pista- 


chio-green) and ash-gray or hair-brown. Trichroic. Streak 
uncolored. ‘Translucent to opaque. Lustre vitreous, a 


284 DESCRIPTIONS OF MINERALS. 


little pearly on 7-7; often brilliant on the faces of crystals. 
Brittle. H.= 6-7. G. = 3°25-3°5. 

Yomposition. A lime-iron-aluminium silicate, the iron 
being mostly in the sesquioxide state and replacing alu- 
minium, and the water basic; and the hydrogen to the cal- 
cium as 1:4. R,Al,0,,Si, = Silica 37°83, alumina 22°63, 
iron sesquioxide 15°02, iron protoxide 0:93, lime 23°27, 
water 2°05 = 100°73. 

B.B. fuses with effervescence to a black glass which 
usually is magnetic. Partially decomposed by hydrochloric 
acid, but if first ignited, is then decomposed, and the solu- 
tion gelatinizes on evaporation. | 

Green epidote is often called Pistacite. Piedmontite is 
a variety containing much manganese, of reddish brown or 
reddish black color. Sucklandite is an iron epidote. 

Diff. The peculiar yellowish green color of ordinary epi- 
dote distinguishes it at once. From zoisite and yesuvianite 
it differs in fusing to a black magnetic globule. The ash- 
gray mineral related to epidote.is mostly zoisite. ! 

Obs. Occurs in crystalline rocks, especially in hornblendic 
rocks. Often occurs in the cavities of amygdaloidal rocks. 
In crystals, six inches long, and with brilliant faces and of 
rich color, at Haddam, Ct.; crystallized also at Franconia, 
N. H.; Hadlyme, Chester, Newbury, and Athol, Mass.; near 
Unity, Amity, and Monroe, N. Y.; Franklin, Warwick, 
and Roseville, N. J.; Pennsylvania, at W. Bradford and H. 
Bradford; Hampton, Yancey Co., N. C.; Michigan, in the 
Lake Superior region; Canada, at St. Joseph. 

Named epidote by Haiiy from the Greek epididimt, to 
increase, in allusion to the fact that the base of the primary 
is frequently much enlarged in the crystals. 


Picroepidote. Supposed to be a magnesian epidote. Siberia. 

Allanite. A cerium epidote, the crystals similar; black to pinchbeck- 
brown; lustre submetallic to pitch-like and resinous. H. = 5°5-6; G. = 
8-4'2; B.B. fuses easily and swells up to a dark, blebby magnetic glass; 
most varieties gelatinize with hydrochloric acid, but not after ignition. 
Norway; Sweden; Greenland; Scotland; Snarum, near Dresden; Tops- 
ham, Me.; Bolton quarry, Mass.; Moriah, Essex Co., Monroe, Orange 
Co., N. Y.; Franklin, N. J.; at East Bradford and Eaton, Pa. ; Amherst 
Co., Va.; in Canada, at St. Paul’s. x 

Orthite. A variety of allanite in long slender crystals: occurs in 
Amelia Co., Va.; N. Carolina. Vasite is altered orthite. Muromontite, 
Bodenite, and Michaelsonite are related minerals. 

Gadolinite. Color greenish-black; monoclinic, with J A [= 116°; 


UNISILICATES. 285 


H. = 6°5-7; G.= 44'5; contains lithium, cerium, and beryllium, with 
SiO. 25 p. c. Sweden; Greenland; Norway. 

Rinkite. Monoclinic; yellowish brown, Titanium-cerium-lan- 
thanum-calcium silicate, with fluorine.. Greenland. 

Mosandriie. Monoclinic. Reddish brown, dull greenish, yellowish 
brown; H. = 4; G. = 2°9-3°03; silicate of cerium, lanthanum, didym- 
ium, calcium, and titanium. Brevig, Norway. 


Zoisite.—Lime-Epidote. 


Orthorhombic; J A J = 116° 40’. Cleavage brachydiag- 
onal, perfect. Also columnar and massive. 

Color ash-gray to white; also greenish gray, red (Thulite). 
Lustre vitreous to sub-pearly. H.=6°6. G. = 3:11-3:38. 

Composition. Like epidote, but with little or no iron. 
That of Ducktown, Tenn., afforded Silica 39°61, alumina 
32°89, iron sesquioxide 0°91, iron protoxide 0°71, magnesia 
0°14, lime 24°50, water 2°12 = 100°88. B.B. swells up and 
fuses to a blebby glass; gelatinizes with hydrochloric acid 
afterignition. Unlike hornblende in its one perfect cleavage. 

Obs. From Saualpe, Carinthia, in the Tyrol; Arendal, 
ete.; Willsboro’ and Montpelier, Vt.; Goshen, Chesterfield, 
ete., Mass.; Unionville and Leiperville, Pa.; Ducktown 
copper-mine, ‘Tenn. 


Saussurite. Fine-grained and tough; white, bluish or yellowish white, 
grayish; G. = 3-3°5. Results from the alteration of a triclinic feld- 
spar, the form or cleavage of which is sometimes retained. The chief 
constituent of the euphotide (p._) of the Alps, Mt. Genevre, Orezza, 
Corsica. Hunt made the saussurite of the Alps (G. = 3°36-3 885), by 
his analyses, a soda-bearing zoisite (silica 43°6 and 48°1).. Most kinds 
are between zoisite and anorthite or labradorite in composition, and 
are apparently altered forms of these feldspars. Has been made a 
mixture of zoisite and a feldspar. A kind from Wildschoénau, having 
G. = 3011, and silica 48°3 p. c., is made by Cathrein such a mixture, 
but more investigation is needed. Altered anorthite crystals from 
Hanover, N. H., of similar characters, with G. = 2°96, have nearly, 
according to Hawes, the composition of Jabradorite (silica 52°52 p. c.). 
The high specific gravity separates the mincral from the feldspars. 

Arctolite. Near zoisite; G. = 3:03. From crystalline limestone. 
Spitzbergen. Balvraidiie, from limestone in Scotland, is of similar 
composition. 

Ilwaite( Yeniie). In orthorhombic striated prisms; J A T= 112° 388’; 
iron-black to grayish black; H. = 5:5-6; G. = 3°7-4°2; in composition 
a calcium-iron silicate in which part of the iron is in the sesquioxide 
state. Elba; Fossum and Skeen, Norway, etc. Reported as occur- 
ring at Cumberland, R. I.; Milk Row quarry, in Somerville, Mass.; 
near Manayunk, Pa. Named Jlvatte from the Latin name of Elba. 

Ardennite. Near Ilvaite in crystals and low p. c. of silica, but 
contains much manganese oxide and more or less of vanadium pent- 
oxide; G. = 3°620; clear yellow to brown. Ardennes, Belgium. 


286 DESCRIPTIONS OF MINERALS. 


Barylite. <A silicate containing 46°23 of baryta; H. = 7; G. = 4°08; 
colorless; the oxygen ratio for bases and silica 10 : 7, or that of a sub- 
Silicate. Longban, Sweden. 

Axinite. 

Triclinic. In acute-edged oblique rhomboidal prisms ; 
PA r=134° AY, rAw=115° 389 P Aaa 
Cleavage indistinct. Also rarely massive or lamellar. 

Color clove-brown; differing somewhat in shade in three 
directions, being trichroic. Lustre vit- 
reous. Transparent to subtranslucent. 
Brittle. H.=6°5-7%. G, =327. Pyro. 
electric. 

Composition. A unisilicate, containing 
boron. One analysis afforded Silica 43°68, 
boron trioxide 5°61, alumina 15°63, iron 
sesquioxide 5°45, manganese sesquioxide 
3°05, lime 20° 92, magnesia 1°70, potash 
0°64 — 100-43. B.B. fuses easily with in- 
tumescence to a dark green or black glass, 
imparting a pale green color to the flame which is due to 
the boron. 

Diff. Remarkable for the sharp thin edges of its crystals, 
their glassy brilliant appearance, and absence of cleavage; 
implanted, and not disseminated like garnet. In one or 
all of these particulars, and also in blowpipe reaction, it dif- 
fers from any of the titanium ores. 

Obs. Occurs at St. Christophe in Dauphiny; Kongsberg 
in Norway; Normark in Sweden; Santa Maria, in Switzer- 
land; Cornwall, England; Thum in Saxony, whence the 
name Thummerstein and Thummnitte. 

In the U. States, at Phippsburg and ae Me.; Cold 
Spring, N. Y.; Bethlehem, Pa. 

Danburite. 

Orthorhombic; J: J = 122° 52’; resembles topaz in its 
crystals. Also massive. Color 
pale-yellow, honey-yellow. ‘Trans- 
parent. Lustre vitreous, slightly 
greasy when massive. H. = 7 
4°25. G. = 2°986-3°021. 

Composition. A calcium-silicate 
containing much boron; (4Ca, 

£B),, O, Si. In an analysis, Si0, 
48°23, B,O, 26°93, Al,O, 0-47, He,0, tr., CaO 23°24, ign. 








MICA GROUP. 287 


0°63 = 99°50. B.B. fuses to a colorless glass; reaction for 
boron, which distinguishes it easily. 

Obs. From Danbury, Ct.; Russell, N. Y., in large crys- 
tals; Switzerland. 

Iolite.—Dichroite. Cordicrite. 

Orthorhombic ; JA J near 120°. Commonly in 6- and 12- 
sided prisms. Also massive. Cleavage indistinct; but crys- 
tals often separable into layers parallel to the base, especially 
after partial alteration. 

Color various shades of blue, looking often like a pale or 
dark blue glass; often deep blue in direction of the axis, and 
yellowish gray transversely. Streak uncolored. Lustre vit- 
reous. ‘Transparent to translucent. Brittle. H.=%-7°5. 
G. = 2°6-2°%. 

Composition. A silicate of aluminium, magnesium, and 
iron, corresponding to Silica 49:4, alumina 33°9, magnesia 
8-8, iron protoxide 7°9= 100. B.B. loses its transparency; 
fuses with much difficulty. 

Diff. Resembles blue quartz, and is distinguished by 
fusing on the edges. Lasily scratched by sapphire. 

Obs. Found at Haddam, Ct., in granite; also in gneiss 
at Brimfield, Mass.; at Richmond, N. H.; at Bodenmais in 
Bavaria; Arendal, Norway; Capo de Gata, Spain; Tunaberg, 
Finland; Norway; Greenland; Ceylon. 

Named from the Greek zon, violet, alluding to its color; 
and dichroite, from dis, twice, and chroa, color, referring 
to the different colors in two directions. 

Occasionally employed as an ornamental stone, and is cut 
so as to present the different shades of color in different di- 
rections. 

Tolite exposed to the air and moisture undergoes a gradual altera- 
tion, becoming hydrous, and assuming a foliated micaceous structure 
so as to resemble talc, though more brittle and hardly greasy in feel. 
Hydrous Iolite, Fahlunite, Chlorophyllite, and Esmarkite are names that 
have been given to the altered iolite; and Gigantolite and a number of 
other like minerals are of the same origin. (See p. 315.) 


MICA GROUP. 


The minerals of the mica group are alike in having (1) 
their crystals monoclinic; (2) the front plane angle of the 
base, or of the cleavage laminz, 120°; (3) cleavage eminent, 
parallel to the base, affording very thin laminex; and (4) 
aluminium and potassiwm among the essential constituents; 


288 DESCRIPTIONS OF MINERALS. 


sodium is often present, but only one species, paragonite, 
contains sodium instead of potassium. In muscovite and 
paragonite the protoxide elements are almost solely the 
alkali metals, with hydrogen (of the water present); in 
phlogopite, they are potassium and magnesium; in biotite 
and some related kinds, potassium, magnesium, and iron; 
in annite, potassium and iron; in cryophyllite, much potas- 
sium and much lithium with some iron. Zinnwalditeis near 
the last. One, @llacherite, contains near 6 p.c. of barium 
with the potassium. Fluorine is present in most mica. 

The combining or oxygen ratio for the bases (the water 
being included) is mostly 1 to 1; but in some kinds the sili- 
con is in excess, and the ratio becomes, at the extreme, 1 to 

4, aS In zinnwaldite and some muscovite. 

The ordinary light-colored micas are mostly muscovite, 
and the black, mostly biotite. ‘The optic-axial plane in 
most micas passes through the longer diagonal of the base, 
being perpendicular to the plane of symmetry. In a black- 
ish Vesuvian mica (meroxene) and in phlogopite and zinn- 
waldite, it passes through the shorter diagonal of the base. 
Lepidolite is a light-colored mica containing lithia, belong- 
ing with muscovite. Muscovite and biotite are so related 
that crystals of the latter often occur that are finished out 
uninterruptedly by muscovite, the axial lines of the one 
continuous with those of the other; and such crystals are 
sometimes several inches across; there is here a compound 
structure chemically, but no twinning in the crystallization. 
When a thin plate of mica is struck with a pointed awl or 
other like tool a symmetrical star of six rays is produced, 
the rays being cleavage lines parallel to the sides of the 
rhombic prism J and the shorter diagonal. 


IMiuscovite.—Common Mica. 

Monoclinic. Usually in plates or scales. ‘Sometimes in 
radiated groups of aggregated scales 
(plumose mica); rarely spheroidal. 

Colors from white through green, 
yellowish and brownish shades; rarely 
rose-red or reddish violet. Lustre 
more or less pearly. ‘Transparent or 
translucent. Tough and elastic. 
H. = 2-2°5. G. = 2°7-3. Optic-axial 
angle 44° to 78°. 

Composition. A common variety has the general formula 





MICA GROUP. 289 


(4R,28),0,,Si,, R including K, and H,, and R, aluminium 
and some iron in the sesquioxide state. An analysis of mica 
of this variety obtained Silica 46°3, alumina 36°8, iron ses- 
quioxide 4°5, potash 9°2, fluorine 0°7, water 1°8 = 99°3; 3 
to 5 p. c. of water often present, and passes thus to a hy- 
drous mica. The variety Phengite contains more silica. 
B.B. whitens and fuses on the thinnest edges with difficulty 
toa gray or yellow glass. Some altered mica exfoliates B.B. 

Diff. Differs from tale and chlorite in being elastic, the 
folia tougher and harder; yet hydrous varieties sometimes 
have a greasy feel, and little or no elasticity. 

Obs. A constituent of granite, gneiss, and mica schist, 
but not as commonly so as biotite. The larger crystalliza- 
tions occur in granite veins, intersecting these rocks. Along 
a belt of country in New England east of the Connecti- 
cut, in New Hampshire, Massachusetts, and Connecticut, 
and to the southwest, in Maryland, Virginia, North Carolina, 
South Carolina, Alabama, and Georgia, large granite veins 
occur, and many valuable deposits of mica have been opened. 
The chief mines of New England are at Alstead, Grafton, 
and Groton, where plates two to three feet across have been 
obtained; mines occur in Virginia, but more important in 
North Carolina, in Yancey, Mitchell, and Macon, and other 
cos.; Dakota affords much mica, chiefly from Custer and 
Pennington cos. in the Black Hills. Mines have been opened 
also in Colorado, New Mexico, etc.; in Canada (Ontario) 
in N. Burgess, Villeneuve, etc. Mica occurs also in in- 
teresting forms at Paris, Me.; Chesterfield, Barre, Brim- 
field, and South Royalston, Mass.; near Middletown and 
Branchville, Ct.; near Greenwood Furnace, Warwick, and 
Edenville, Orange Co., and in Jefferson and St. Lawrence 
cos., N. Y.; Newton and Franklin, N. J.; near German- 
town, Pa.; Jones’s Falls, Md. 

Mica was formerly used in Siberia for glass in windows, 
whence it has been called Muscovy glass. It is in common 
use in lanterns; for the doors of stoves and furnaces and 
for other purposes which demand a tough transparent sub- 
stance not easily affected by heat. It is also ground for 
some ornamental purposes. About 150,000 pounds of sheet 
mica ($370,000) was the product in the United States for 
1884, and 92,000 pounds ($161,000), for 1885. 

Lepidolite. A lithium-bearing muscovite; color rose-red, and lilac 
to white; in crystalline plates and aggregations of scales. It contains 

19 


290 DESCRIPTIONS OF MINERALS. 


from 2 to 5 per cent of lithia, and hence B.B. imparts a deep crimson 
color to the flame. It is mostly of the species muscovite, and the rest 
is zinnwaldite. The formula, Lik Al.O.F.Sis = Silica 49°18, alumi- 
na 27°87, lithia 4°09, potash 12°81, fluorine 9°84 = 103°79. Rozena, 
Moravia; Saxony; the Ural; Sweden; Cornwall; Paris, Hebron, etc., 
Maine; Chesterfield, Mass.; Middletown, Ct. The red mica of Goshen 
is not lithium-bearing. 

Margurodite, Hygrophilite, Damourite, Sericite, Sterlingite. Names 
for micas related to muscovite, but containing 4 or 5 per cent. of 
water. While mica becomes hydrated on weathering, much mica 
was hydrous at its origin. A hydrous mica is distinguished by its 
greasy feel and little elasticity. The compact pseudomorphous mate- 
rial called Pinzte has the constitution of a hydrous mica. 

Gillacherite. Like whitish muscovite in its elastic lamine, polariza- 
tion, and other characters; but an analysis obtained only 7°6 p. c. of 
potash (with 1°4 of soda), along with about 5 p.c. of baryta, and 
4:4 of water. Kemmat, in Pfitschthal. 

Paragonite. Resembles much muscovite; occurs in pearly scales 
constituting a schistose rock; G. = 2°75-2°9; formula like that given 
under muscovite; an analysis afforded Silica 46°81, alumina 40°06, mag- 
nesia 0°65, lime 1°26, soda 6°40, water 4°82 = 100. Monte Campione,, 
in the region of St. Gothard. Pregrattite and Cossaite are the same. 

Cryophyllite. Like a green muscovite and similar in optic-axial 
angle. G. =2°909. But an analysis obtained, besides 13°15 p. c. of 
potash, 4 of lithia and 8 of iron protoxide, with 2°49 of fluorine; an- 
other 10°6 of K.O, O°8 0f Na.O, 4°9 of Li.O, and about 7.1 of fluorine. 
Owing apparently to the unusual percentage of alkali and fluorine, 
it is remarkable tor its fusibility, it fusing in the flame of a candle; to 
this the name, from the Greek kruos, ice, alludes. The granite of 
Cape Ann, Mass. 

Zinnwaldite is similar to the last in containing iron and lithium 
without magnesium, but the amount of alkali metal is proportionally 
less, and fusion is less easy. Zinnwald. 

’ aria losses is very similar, but contains 59 p. c. SiOx. Green- 
and. 


Phlogopite. 


Monoclinic. Color often yellowish brown with a copper- 
like reflection; also brownish yellow to white. Optic-axial 
angle 3° to 20°. 

Composition. Mostly (?R,4A1),0,,51,,1n which (HK): 
Mg=1to5. An analysis afforded Silica 43:00, alumina 
12°37, iron sesquioxide 1°71, magnesia 27°70, potash 10°32, 
soda 0°30, water 0°38, fluorine 5°67 = 102°35. B.B. like 
muscovite, but reaction for more fluorine. 

Obs. From the crystalline limestone of St. Lawrence, 
Jefferson, Essex, and Orange cos., N. Y., and Sussex Co., 
N. J.; Burgess, Canada, etc. 

Aspidolite is a related mica. 


MICA GROUP. 291 


Biotite. 


Monoclinic. Crystals usually short, erect, rhombic or 
hexagonal prisms. ‘Twins of six individuals not infrequent, 
as optically detected. Common in disseminated scales; 
also in masses made up of an aggregation of scales. 

Color dark green to black, rarely white. Transparent to 
opaque. Lustre more or less pearly on a cleavage surface. 
Optic-axial angle often less than 1°; crystals often appar- 
ently uniaxial. H. = 2°5-3. G. = 2°7-3°1. 

Composition. Mostly (R,3R),0,,Si,, in which R = iron, 
magnesium, potassium, and hydrogen (of water present), 
and R=aluminium. In one analysis, Silica 40°00, alumina 
17°28, iron sesquioxide, 0°72, iron protoxide 4°88, magnesia 
23°91, potash 857, soda 1°47, water 1°37, fluorine 1°57 = 
99°77. B.B. whitens and fuses on thin edges; sometimes a 
red flame from reaction for lithium. ‘This species has been 
called Anomite. Huchlorite is biotite. The approach to 
uniaxial character optically in this mica has been explained 
by J. P. Cooke on the view of a twinning between succes- 
Sive lamine, making an overlapping compound structure. 

Obs. Common as a constituent of mica schist, gneiss, and 
granite, much more common than muscovite; often pres- 
ent in syenyte; occurs in black scales in some trachytes. 
While differing from muscovite in the presence of magne- 
sium and iron, the percentage of potash is but little less 
(about 9 per cent.). Occurs in large black, greenish, and 
brownish-black crystallizations at Greenwood Furnace, Mon- 
roe, N. Y.; in veins in granite at Middletown, Portland, and 
Stony Creek, Ct., a kind affording lithia reactions, and 
oxidizing easily; Moriah, Essex Co., N. Y.; Topsham, Me., 
crimson; Easton, Pa., white. 


Meroxene. The so-called biotite, or black mica, of Vesuvius; unlike 
biotite, it has the optic-axial plane parallel (instead of at right-angles 
to) the plane of symmetry. 

Lepidomelane. Resembles biotite, but thin folia are but little elastic, 
or are brittle,and the proportion of iron oxide is larger (20 to 30 p. c.), 
with less magnesia (3 to 7 p. c.). Wermland, Sweden. 

Haughtonite. Between biotite and lepidomelane. Contains 7 to 15 
p.c. of magnesia. Fuses with diificuity. From granite, dioryte, etc., 
of Ireland. 

Annite. Related to lepidomelane, but contains almost no magnesia 
(0°60 p. c.). From Cape Ann. Another, of same loc., contains less 
silica (82 p.c.) and much more FeO (80°83). Annite crystals have 
sometimes a border of cryophyllite. 


292 DESCRIPTIONS OF MINERALS. 


Siderophyllite. Like Annite in the near absence of magnesia (1:14 
p. c.); B.B. fuses easily. From Pike’s Peak. 

Astrophyllite. A mica of doubtful relations; has been referred to the 
pyroxene group; has the small amount of silica (82-35 p.c.) that char- 
acterizes the chlorite group, and 3°5-4'5 p. c. of water; contains be- 
sides iron protoxide, 7 to 14 p. c. of titanium dioxide and some zirconia 
and potash. Norway; El Paso Co., Col. 


SCAPOLITE GROUP. 


The Scapolite species are tetragonal in crystallization, 
usually white in color or of some light shade, and analyses 
afford alumina and lime with or without soda. The lime 
scapolites are unisilicate in ratio; the others, containing 
alkali, have, with one exception, more silica than this ratio 
requires. 

Wernerite.—Scapolite. 


Tetragonal; 1 A 1 = 136° 7’. Cleavage rather indistinct 
parallel with 7-1 and J. Also massive, 
sublamellar, or sometimes faintly fi- 
brous in appearance. 

Colors light; white, gray, pale blue, 
greenish or reddish; brown when im- 
pure. Streak uncolored.  ‘T'rans- 
parent to nearly opaque. Lustre usu- 
ally a little pearly. H.=5-6. G.= 
2°65-2'8. 

Composition. (4[Ca, Na, |2A1),0,,Si, 
= Silica 48°4, alumina 28°5, lime 181, soda 5:0 = 100; but 
contains also 1 to 2°5 p. c. of chlorine. B.B. fuses easily 
with intumescence to a white glass; imperfectly decomposed 
by hydrochloric acid. : 

Diff. The square prisms and the angle of the pyramid at 
summit are characteristic. In cleavable masses it resembles 
a feldspar, except for a slight fibrous appearance usually dis- 
tinguished on the cleavage surface. More fusible than 
feldspar, and of higher specific gravity. Spodumene has a 
much higher specific gravity, and differs also B.B. Wollas- 
tonite is more fibrous in the appearance of the surface, is 
less hard, and gelatinizes with acids. 

Ols. Found mostiy in the older crystalline rocks, and 
also in some volcanic rocks; especially common in granular 
limestone. Crystals occur at Gouverneur, Two Ponds, 
Amity, N. Y.; Bolton, Boxborough, Littleton, Mass.; 





SCAPOLITE GROUP. 293 


Franklin, Newton, N. J.; massive at Marlboro’, Vt.; West- 
field, Mass.; Monroe, Tyringham, Ct. Foreign localities are 
at Arendal, Norway; Wermland, Sweden; Pargas in Finland. 


Chelnsfordite, Nuttallite, Ontariolite, Glaucolite, are varicties of this 
species. Paranthine and Hkebergite are similar, being distinguishable 
from it only by chemical analysis. 

Sarcolite. 'Vetragonal and like wernerite; reddish white to rose-red; 
H. = 6; G. = 2°9-2°95; formula (4Ca3$Al).0..8i;; gelatinizes with 
acids. In small geodes, Mt. Somma. 

Meionite. A lime scapolite, like wernerite in crystals, but having 
the formula (4CazA]).0,.Sis, being a true unisilicate. Monte Somma. 

Dipyre is near wernerite, but contains more silica (56 p. c.) and 10 
per cent. of soda. The Pyrenees. 

Mizzonite and Marialite are other kinds containing much soda and 
Silica, the latter 60 p. c. 


Nephelite.— Nepheline. 


Hexagonal. In hexagonal prisms with replaced basal 
edges; O \1=135° 55’. Also massive; rarely thin colum- 
nar. 

Color white, or gray, yellowish, greenish, bluish red. 
Lustre vitreous to greasy. ‘Transparent to opaque. H. = 
55-6. G. = 2'55-2°62. . 

Composition. (Na,, K,),A1,0,,8i,, the oxygen ratio being 
1:3:43. An analysis afforded Silica 44:0, alumina 33:3, 
FeO,, MnO, 0:7, lime 1°8, soda 15:4, potash 4°9, water 0°2 
= 100-3; alittle lime is usually present. B.B. fuses quietly 
to a colorless glass. Decomposed by hydrochloric acid, and 
the solution gelatinizes easily on evaporation. 

Named from the Greek nephelé, cloud, the mineral becom- 
ing clouded in acid. Includes the glassy crystals from Ve- 
suvius called Somme; also hexagonal crystals in other 
volcanic rocks; a massive variety, of greasy lustre, called 
Hleolite from the Greek elaion, oil. Altered crystals are 
in part the mineral Gieseckite. 

Diff. Distinguished from most scapolites and feldspars 
by the greasy lustre when massive, and the facility with 
which it gelatinizes with acids; from apatite by the las 
character, and also its greater hardness. 

Obs. The prominent constituent of nephelindoleryte or 
nephelinyte, and phonolyte, and also in some other eruptive 
rocks; enters into the constitution of miascyte, zircon- 
syenyte, and some metamorphic rocks. Among the localities 
are Vesuvius and C, di Bove, in Italy; Katzenbuckel, near 


294. DESCRIPTIONS OF MINERALS. 


Heidelberg; Aussig, in Bohemia; and as eleolite, Brevig, 
Norway; Siberia; the Ozark Mountains, Arkansas; Litch- 
field, Maine. . 


Cancrinite. Like nephelite in crystallization, also in composition, 
except the presence of some carbonates and usually water; color white, 
gray, yellow, green, blue, or reddish; H. = 5-6; G. = 2°4-2°5; on 
account of the carbonates it effervesces in acids. B.B. fuses very 
easily. 

Deere in crystalline rocks at Miask in the Ural; in Norway; Tran- 
sylvania; and at Litchfield in Maine, with eleolite and sodalite. 

Microsommite. Near nephelite in form; also in composition, except 
the presence of much chlorine (6°2 to 8 p. 
c.) and sulphuric acid (4 to 5°26 p. c.); col- 
orless to yellow. In large crystals from 
Mt. Somma; and in small from bombs 
ejected by Vesuvius in 1872. Davyne is 
in part altered microsommite. 

Hueryptiie. Hexagonal. Crystallized 
microscopically within albite, in forms 
like those of the quartz of graphic granite, 
as in the figure. Composition LizAl0;Sia, 
near that of nephelite. Both the albite 
and eucryptite a result of the alteration of 
spodumene, at Branchville, Ct.; and shown by Brush and E. 8 
Dana to be an intermediate stage in the change from spodumene to 
muscovite. Gelatinizes in acid. 





Sodalite. 


Isometric. In dodecahedrons; cleavage dodecahedral. 
Color brown, gray, or blue. Lustre vitreous, sometimes 
greasy. H.=6. G. = 2°25-2°4. 

Composition. Na,AlO,Si, + 4NaCl = Silica 37:1, alumina 
31°7, soda 19°2, sodium 4°7, chlorine 7°3 = 100. B.B. 
fuses with intumescence to a colorless glass. Decomposed 
by hydrochloric acid, and the solution gelatinizes on evapo- 
ration. 

Occurs in eruptive and metamorphic rocks. Found im 
Sicily; near Lake Laach; at Miask; in Norway; W. Green- 
land; Bolivia; blue, at Litchfield, Me.; lavender-blue at 
Salem, Mass. | 


Haiiynite (or Hauyne). Near sodalite in form and composition; 
blue to greenish; contains about 12 p. c. of sulphuric acid. From 
lavas of Mt. Somma; L. Laach; Mt. Dor, etc. Vosite (or nosean) is 
similar. Jtinertte and Skolopsiie are altered hatiynite or nosite. 


SCAPOLITE GROUP. 295 


Lapis-Lazuli.— Ultramarine. 


Isometric; rarely in crystals (dodecahedrons); cleavage 
imperfect. Usually massive. Color rich Berlin or azure 
blue. Lustre vitreous. Translucent to opaque. H. = 5°5. 
G. = 2°3-2°5. 

Composition. Silica 45°5, alumina 31°8, soda 9:1, lime 
3°5, iron 0°8, sulphuric acid 5°9, sulphur 0°9, chlorine 0°4, 
water 0'1=98°0. B.B. fuses to a white translucent or 
opaque glass, and if calcined and reduced to powder, loses 
its color in acids. Color supposed to be due to sodium 
sulphide. The mineral is not homogeneous, but the exact 
nature of the ultramarine species at the basis of it is not yet 
ascertained. 

Obs. Found in syenyte and granular limestone. Brought 
from Persia, China, Siberia, and Bucharia. The specimens 
often contain scales of mica and disseminated pyrites. 

The richly-colored lapis-lazuli is highly esteemed for 
costly vases, and for inlaid work, and is used also in the 
manufacture of mosaics. It is the material of the beautiful 
and durable blue paint called Ultramarine, which has been 
a costly color. An artificial ultramarine is made which 
is equal to the native, and comparatively cheap; it con- 
sists of silica 45°6, alumina 23°3, soda 21°5, potash 1°7, 
lime ¢race, sulphuric acid 3°8, sulphur Lev arom tl; and 
chlorine a small quantity undetermined. 


Leucite.—Amphigene, 


Isometric. orm the trapezohedron, as in the figure. 
Cleavage imperfect. Usually in dull glassy 
white to gray crystals, disseminated through 
lava. ee eilacan: to opaque. H. = 5°5-6. oe 
G. = 2°45-2°5. Brittle. 

Composition. K,Al0,,Si, = Silica 55:0, 
alumina 23°5, potash 21°5= 100. B.B. in- I [-/ 
fusible. Moistened with cobalt nitrate and 
ignited assumes a blue color, Decomposed 
by hydrochloric acid, without gelatinizing. 

Diff. Distinguished from analcite by its hardness and in- 
fusibility. 

Obs. In volcanic rocks, and abundant in those of Italy, 
especially at Vesuvius, where some crystals are an inch in 
diameter. Also found in the Leucite Hills, northwest of 


296 DESCRIPTIONS OF MINERALS. 


Point of Rocks, Wyoming Territory; in Cerro de los Vir- 
gines, Cal. 

Named from the Greek /ewkos, white. The crystals give 
usually the angles of a tetragonal form, but this is believed 
to be an irregularity due to the internal condition of the 
crystal (p. 79). 


FELDSPAR GROUP. 


The species of the Feldspar Group are related— 

A. In crystallization: (1) the forms being all oblique ; 
(2) the angle of the fundamental rhombic prism J, in each, 
nearly 120°; (8) the other angles differing but little, al- 
though part of the species are monoclinic and part tri- 
clinic; and (4) there being two directions of easy cleavage, 
one, the most perfect, parallel to the basal plane O, and the 
other parallel to the shorter diagonal section, with the in- 
tervening angle, “the cleavage angle,” either 90° (as in the 
monoclinic species orthoclase and hyalophane), or nearly 
90° (as in the triclinic species). The triclinic feldspars are 
often called by the general name Plagioclase. 

B. In composition: (1) the only element in the sesquiox- 
ide state being aluminium, and those in the protoxide state 
potassium, sodium, or calcium, or two or three of these 
bases together, rarely with barium; (2) the constant ratio 
of 1 atom of R to 1 of BR; (8) the amount of silica in the 
species increasing with the proportion of alkali, being that 
of a unisilicate in the pure lime-feldspar, anorthite; that 
of a tersilicate in the soda-feldspar, albite, or potash-feld- 
spar, orthoclase; and so directly proportioned to the alkali, 
that the amount in any lime-and-soda feldspar may be 
deduced by taking the lime (or calcium) as existing in the 
state of a unisilicate, and the soda in that of a tersilicate, 
and adding the two together. 


Anorthite has the formula CaA1O,Si,. 
Albite Ai 4 Na,A10, ,Si,. 

The constitution of a species containing Ca and Na, in 
the ratio of 1 to 1 for the protoxide portion may be ob- 
tained as follows. Adding together the anorthite and albite 
formulas, we have CaNa,Al,O,,Si,; then dividing by 2, the 
formulas become 4CazNa,AlO,.5i,, which expresses the 
composition of andesite. With 3 parts of the Ca unisili- 
cate, and 1 of the Na, tersilicate, the composition is that 


FELDSPAR GROUP. 297 


of labradorite. So it is for other combinations, that is for 
other species between anorthite and albite in composition ; 
and since still other intermediate kinds exist, it is supposed 
that all the varieties between the two above-mentioned 
species are isomorphous combinations of them. 

The quantivalent or oxygen ratio for the R, Al, Si, in the 
several species of the group, is as follows: V means ¢riclinic 
in crystallization, and IV monoclinic; and K, Na, Ca, Ba, 
the protoxide basic element of the species. 


SYSTEM OF SYSTEM OF 
RATIO. CRYSTALLI- RATIO. CRYSTAL- 
ZATION. LIZATION, 


Anorthite. Ca, 1 
Labradorite, Ca, Na, 1 
Hyalophane, Ba, a 
Andesite, Na, Ca, 1 


23:4 V,  Oligoclase, Na, Ca,1:3:9 he 
no 0 Vs Albite, Na, ° 133312 Vv. 
23:8 IV, Microcline, K, 1235125 - NV. 
$3:8 Vv; Orthoclase, K, P33 12% NV: 

These are the normal ratios; but there is variation from 
them in the analyses, part of which is variation in actual 
composition, and part a result of interlamination or mixture 
of two feldspars. Thus, orthoclase occurs mixed with 
microcline, albite, or oligoclase. But while such mixtures 
account for the soda found in some analyses of orthoclase, 
it does not for that in all, since soda does occur in many 
specimens of pure orthoclase, replacing part of the potash. 
It is the same with the triclinic feldspar microcline, which 
has the composition of orthoclase, and may have the alkali 
portion all potash or part soda, one analysis of typical 
microcline giving only 0°48 of soda. It is, hence, not safe 
to calculate the percentage of orthoclase present in a feld- 
spar, or in amixture, from the percentage of potash. More- . 
over, potash is present in much albite. 

The above ratios show that anorthite has for the oxygen 
ratio between R-+ Rand Si, 4: 4, or 1:1, as in true uni- 
silicates; while in albite and orthoclase, the same ratio is 
4:12 or1: 3, that of a tersilicate, as above stated. 

OC. In physical characters: hardness between 6 and 7; 
specific gravity, between 2°44 and 2°75; lustre vitreous, 
but often pearly on the face of perfect cleavage ; and each 
species transparent to subtranslucent. 

Distinctive characters. The form is sufficient to deter- 
mine a feldspar when it is in defined crystals; so also the 
fact of two unequal cleavages inclined to one another at 
84° to 90°, one of them quite perfect. - No fibrous, colum- 
nar, or micaceous varieties are known. ‘They differ from 


298 DESCRIPTIONS OF MINERALS. 


rhodonite, by the absence of a manganese reaction ; from 
spodumene, by the absence of a lithia reaction as well as 
cleavage angle; from scapolite, by form; from nephelite, by 
form, and also more difficult fusibility, and by not gelatiniz- 
ing with acids, except in the case of anorthite, which gela- 
tinizes readily. For optical characters see page 78, and 
beyond, under Petrology. 


Anorthite.—Indianite. Lime Feldspar. 


Triclinic; cleavage angle 85° 50’ and 94° 10’.. Crystals 
tabular. Also massive granular or coarse lamellar. Color 
white, grayish, reddish. G. = 2°66-2°78. 

Composition. - CaAlO,Si, = Silica 43:1, alumina 36:8, 
lime 20°'1= 100. 3B.B. fuses with much difficulty to a 
colorless glass; decomposed by hydrochloric acid, and the 
solution gelatinizes on evaporation. 

Obs. Occurs in basic eruptive rocks; also in some meta- 
morphic rocks. ound in the lava of Vesuvius; the Tyrol; 
Faroe Islands, Iceland; in imbedded crystals in some doler- 
yte of the Connecticut Valley; in altered crystals (saussur- 
ite) at Hanover, N. H.; in diabase and gabbro of Keweenaw 
Point; as a rock with large crystals on the north or Min- 
nesota shore of L. Superior. Barsowite is referred here. 


Bytownite. Near anorthite, but having more silica (46-48 p. c.), with 
some soda, and the oxygen ratio 1:3:5. The Minnesota anorthite 
gives the unusual ratio 1; 2°4: 4°15. 


Labradorite.—Lime-soda Feldspar. Labrador Feldspar. 


Triclinic; cleavage angle 93° 20’ and 86° 40’. Usually 
in cleavable massive forms. 

Color dark gray, brown, or greenish brown; also white or 
colorless. Often a series of bright chatoyant colors from 
internal reflections, especially blue and green, with more or 
less of yellow, red, and pearl-gray. G. = 2°67-2°70. 

Composition. }#CaiNa,AlO,,Si, = Silica 52°9, alumina 
30°3, lime 12°3, soda 4°5 = 100. Sometimes a little potash 
in place of the soda. 3B.B. fuses easily to a colorless glass. 
Only partially decomposed by hydrochloric acid. 

Obs. A constituent of the larger part of basic eruptive 
rocks and lavas; and also of some metamorphic rocks, An 
ingredient in part of the Archean rocks. Named from its 
first discovery in Labrador. 


FELDSPAR GROUP. 299 


Andesite. Triclinic; cleavage angle 87°-88°. Near labradorite in 
composition; the formula 4Cat}NazAlO.28i, = Silica 59°8, alumina 
25°5, lime 7:0, soda 7°7 = 100°0. 

Hyalophane. Monoclinic, and, hence, the cleavage angle 90°. A 
baryta feldspar; the formula like that of andesite, excepting the sub- 
stitution of Ba for Ca and K, for Naz. G. = 2°8-2°9. Binnenthal, 
Switzerland; Jakobsberg, Sweden. 

A triclinic baryta-feldspar, having the ratio of andesite, 1: 3:8, 
and the cleavage angle 86° 37’ with G. = 2°835, has been described ; 
it approaches oligoclase in optical characters. 


Oligoclase.—Soda-lime Feldspar. 


Triclinic; cleavage angle 93° 50’ and 86° 10’. Commonly 
in cleavable masses. Also massive. 

Color usually white, grayish white, grayish green, green- 
ish, reddish. Transparent, subtranslucent. H. = 6-7. 
G. = 2°5-2°7. 

‘ Composition. +4Ca?Na,Al0,,Si, = Silica 61:9, alumina 
24:1, lime 5°2, soda 8°38 =100. A portion of the soda is 
usually replaced by potash. B.B. fuses without difficulty; 
not decomposed by acids. 
- Obs. Occurs in granite, gneiss, syenyte, and various 
metamorphic rocks, especially those containing much silica; 
and in such case usually associated with orthoclase. Sw2- 
stone is in part oligoclase, giving bright reflection from the 
interior, owing to disseminated scales of hematite. Occurs 
in Norway. Moonstone is in part a whitish opalescent 
variety. Oligoclase occurs at Unionville, Blue Hill, Pa.; 
Haddam, Conn.; Mineral Hill, Del.; Chester, Mass., etc.; 
the Urals; Finland; Norway; Bohemia; Elba. 


Albite.—Soda Feldspar. 


Triclinic. Cleavage angle 93° 36’, and 86° 24’. Figures 
1 to 6 represent some of its forms; 2 and 3 are twin 
crystals. Crystals usually more or less thick tabular. Also 
massive, with a granular or lamellar structure. Color 
white; occasionally light tints of bluish white, grayish, 
reddish, and greenish. ‘Transparent to subtranslucent. 
H. = 6-7. G. = 2:61-2:62. 

Composition. Na,AlO,,Si, = Silica 68°6, alumina 19°6, 
soda 11°38 =100°0. B.B. fuses to a colorless or white glass, 
imparting an intense yellow to the flame. Not acted upon 
by acids. 


300 DESCRIPTIONS OF MINERALS. 


Cleavelandite is a lamellar variety occurring in wedge- 
shaped masses at the Chesterfield albite vein, Mass. 





Obs. Albite occurs in some granites and gneiss, and is 
most abundant in granite veins. Fine crystals occur at 
Middletown, Haddam, and Branchville, Ct.; Goshen, Mass. ; 
Granville, N. Y.; Unionville, Delaware County, Pa. 

Named from the Latin albus, white. 


Microcline.—Potash Feldspar. 


Triclinic; cleavage angle within 16’ of 90°. In angles, 
and also in physical characters, nearly identical with ortho- 
clase, but the cleavage surface shows sometimes the fine 
striations due to twinning. When viewed with polarized 
light, the twinned structure is distinct, but differs from other 
triclinic feldspars in a blocked arrangement, owing to a 
transverse twinning (Fig. 13, p. 79). Colors white, flesh- 
red, copper-green. ‘The green variety has been called 
Amazon-stone ; the color comes, according to Kénig, from 
the presence of an organic salt of iron. 

Occurs in the zircon-syenyte of Norway; also in the 
Urals; Greenland; Labrador; Leverett, Mass.; Branchville, 
Ct.; Delaware; Chester Co., Pa. (Chesterlite); White Moun- 
tain Notch; Pike’s Peak (Amazon-stone); Magnet Cove, Ark. 


Orthoclase.-—Common Feldspar. Potash Feldspar. 


Monoclinic; the cleavage angle 90°. Figures 1 to 3 
represent common forms, and 4 to 8, twins; 4, twinned 


FELDSPAR GROUP. 301 


parallel to O; 5, 6, parallel to 7-2, Carlsbad twins; 7, par- 
allel to 2-2, Baveno twin; 8, same as 7, but made up of four 
crystals instead of two. Usually in thick prisms, often 





rectangular, and also in modified tables. Also massive, with 
a granular structure, or coarse lamellar; also fine-grained, 
massive, crypto-crystalline. Colors light; white, gray, and 
flesh-red common; also greenish and bluish white and green. 
H.= 6. G. = 2°55-2°58. 

Composition. K,AIO,,8i, = Silica 64:7, alumina 18:4, 
potash 16°9 = 100. Soda sometimes replaces a portion of 
the potash. B.B. fuses with difficulty; not acted on by 
acids. 

Common feldspar is the common subtranslucent variety; 
Adularia, the white or colorless subtransparent, the name 
derived from Adula, one of the highest peaks of St. Gothard; 
Sanidin or glassy feldspar, transparent tabular crystals, 
often occurring in trachytes and lavas; but some of the 
“‘ slassy feldspar” belongs to the species oligoclase or anor- 
thite; Loxoclase, a grayish variety, with a pearly or greasy 
lustre, that contains much soda. 

Moonstone is an opalescent variety of adularia, having 
when polished peculiar pearly reflections. Swzstone is simi- 
lar; but contains minute scales of mica. Aventurine feld- 
spar often owes its iridescence to minute crystals of hema- 
tite, ilmenite, or githite. Sunstone and moonstone are 
mostly oligoclase, and so is a large part of aventurine feld- 
spar. 


302 DESCRIPTIONS OF MINERALS. 


Diff. Distinguished from the other feldspars by its right- 
angled cleavage and the absence of striated surfaces. 

Obs. One of the constituents of granite, syenyte, gneiss, 
and other related rocks; also of porphyry, and trachyte; 
and it often occurs in these rocks in imbedded crystals. 
St. Lawrence Co., N. Y., affords fine crystals; also Orange 
Co., N. Y.; Haddam and Middletown, Conn.; Acworth, 
N. H.; South Royalston and Barre, Mass., etc.; Lenni, Pa. 
(Lennilite and Delawarite). Green feldspar occurs at 
Mount Desert, Me.; an aventurine feldspar at Leiperville, 
Penn.; adularia at Haddam and Norwich, Conn., and Par- 
sonsfield, Me. A fetid feldspar (sometimes called Necronite) 
is found at Roger’s Rock, Hssex Co., N. Y.; 21 miles from 
Baltimore, Md. Carlsbad and Elbogen i in Bohemia; Baveno 
in Piedmont; St. Gothard; Arendal in Norway; Land’s End; 
the Mourne Mountains, Ireland; are some of the more in- 
teresting foreign localities. Cassinite, from near Media, . 
Pa., contains much intercalated albite. 

Felsite is compact, uncleavable orthoclase, having the 
texture of jasper or flint, which it much resembles. It 
generally contains disseminated silica. Colors various, as 
white, gray, brown, red, brownish red and black; sometimes 
banded. It is distinguished from flint or jasper by its 
fusibility. It is the material of beds or strata in some 
rock formations, and also of dikes or masses of eruptive 
rocks. It is the base of much red porphyry. ‘The vicinity 
of Marblehead, Mass. ., 18 one of its localities. 

The name feldspar i is from the German word Feld, mean- 
ing field. It is, therefore, wrong to write it felspar. 

Orthoclase is used extensively in the manufacture of por- 
celain. ‘The large granite veins of Middletown, Portland, 
and Branchville, Conn., are quarried in several places for 
this purpose. 

Kaolin. ‘This name is applied to the clay that results 
from the decomposition of feldspar. See Kaolinite, p. 332. 


Soda-orthoclase. A. monoclinic soda-feldspar from Pantellaria ; 
differing from typical orthoclase in having two thirds | alomce at of 
the potassium replaced by sodium. 


III. SUBSILICATES. 


In the Subsilicates, as stated on page 262, the combin- 
ing or quantivalent ratio between the bases and silica is 1 


SUBSILICATES. 303 


to less than 1. In Chondrodite, the first of the following 
species, the ratio is 4: 3; in Tourmaline, Andalusite, Cya- 
nite, and Fibrolite, 3:2. Analyses of Andalusite obtain 1 
of alumina, AlO,, to 1 of silica, Si0,, giving the oxygen 
ratio for bases and silica 3:2, which is the composition 
also of cyanite and fibrolite; the three species, andalusite, 
cyanite, and fibrolite are the same in constituents and 
atomic ratio, while differing in crystalline form, exemplify- 
ing a case of ¢rimorphism among minerals. 

The ratio 3:2 exists also in Topaz, Euclase and Da- 
tolite, in 'Litanite or sphene, and in Keilhauite. In Stau- 
rolwe, the ratio is 2:1. In datolite and tourmaline the 
basic constituents include boron; in titanite and keilhauite, 
titanium; in datolite, euclase, and part of staurolite, hy- 
drogen, that is, the hydrogen of the water found on analy- 
sis. In chondrodite, topaz, and some tourmaline, fluorine 
replaces part of the oxygen. 


Chondrodite.—Humite in part (Scacchi’s Type II.). 


Monoclinic. Cleavage indistinct. Usually in imbedded 
graing or masses. Color light yellow to brownish yellow, 
yellowish red, and garnet-red. Lustre vitreous, inclining 
a little to resinous. Streak white, or slightly yellowish or 
grayish. Translucent to subtranslucent. Fracture uneven. 
H. = 6-6°5. G. =3-1-3°25. 

Composition. Mg,0,,Si, (= 8MgO + 3810,); but a por- 
tion of the magnesium replaced by iron, and a part of the 
oxygen by fluorine. A specimen from Brewster’s, New 
York, afforded Silica 34:1, magnesia 53°7, iron protoxide 
7°83, fluorine 4°1, with 0°5 of alumina = 99°7. 

B.B. infusible. Decomposed by bydrochloric acid; solu- 
tion gelatinizes on evaporation. Reacts for fluorine. 

Diff. Unlike tourmaline or garnet, some brownish-yel- 
low varieties of which it approaches in appearance, it does 
not fuse, and reacts for fluorine. Named from the Greek 
chondros, a grain. 

Obs. Abundant in Sussex Co., N. J., and Orange Co., 
N. Y., occurring at Sparta and Bryam, N. J., and in War- 
wick and other places in N. Y.; at the Tilly Foster Iron 
Mine, Brewster’s, Putnam County, N. Y., it is very abund- 
ant; found also west of Kent, and in Norfolk, Ct.; East Lee, 
Tyringham, and Hinsdale, Mass. At Vesuvius it occurs 
in small crystals. 


304 DESCRIPTIONS OF MINERALS. 


The species was early named Chondroddite, from Finland 
specimens. Afterward, small crystals, found in the lavas 
of Somma (Vesuvius) were named Humite, and both were 
later referred to the same species. Now three species of 
different angles and form, but related composition and 
physical character, are recognized—the above and the fol- 
lowing: 

Humite. Orthorhombic; embraces part of Humite 
(Scacchi’s Type I.), and some large crystals found at Brews- 
ter’s, N. Y., and others of Sweden. 

Clinohumite. Monoclinic; includes Scacchi’s Type II. 
of Humite, and some of the crystals from Brewster’s. 


Tourmaline. 
Rhombohedral; RA R = 103°,—4A —4 = 133° 8’. Usual 
in prisms of 3, 6, 9, or 12 sides, terminating in a low 3-sided 
pyramid; sides of the prisms often rounded and striated. 


A. 2. 3. 4, 





Crystals often having unlike planes at the two extremities, 
as shown in figure 3. Also compact massive, and coarse 
columnar, radiating or divergent from a centre. 

Color black, blue-black, and dark brown, common ; also 
ruby-red, pale red, rich grass-green, cinnamon-brown, yel- 
low, gray, and colorless. Sometimes red within and green 
externally, or one color at one extremity and another at the 
other. Transparent; usually translucent to nearly opaque. 
Dichroic. Lustre vitreous, inclining to resinous on a sur- 
face of fracture. Streak uncolored. Brittle; the crystals 
often fractured across and breaking very easily. H. = 7-0- 
75. G. = 2°89-3°3. 

Composition. (R,, B,,B,) O,Si,, in which R includes, in 
different varieties, Fe, Mg, Na,, with often traces also of 
Ca, Mn, K,, Li,; R includes aluminium, with some boron 
in the trioxide state replacing Al; and a little of the oxygen 
is sometimes replaced by fluorine. “= 


SUBSILICATES. 305 


Black, from Haddam, afforded on analysis, Silica 37°50, 
boron trioxide (by loss) 9°02, alumina 30°87, iron protoxide 
8°54, magnesia 8°60, lime 1°33, soda 1°60, potash 0°73, 
water 1°81 =100. <A red from Paris, Maine, afforded 
Fluorine 1:19, silica 41°16, boron trioxide (by loss) 8°93, 
alumina 41°83, manganese protoxide 0°95, magnesia 0°61, 
soda 1°37, potash 2°17, lithia 0°41, water 2:57 = 100. 

Varies in color with the composition; the dark contain 
much iron and the light colors but little. Mudellite is red; 
Indicolite (from Indigo) blue and bluish black; Achroite, 
colorless. Schorl formerly included the common black 
tourmaline, but the name is not now used. 

The presence of boron trioxide is a remarkable feature of 
this mineral. ‘The colorless, red, and pale-greenish kinds 
usually contain lithia. B.B. the darker varieties fuse with 
ease, and the lighter with difficulty. On mixing the 
powdered mineral with potassium bisulphate and fluor spar, 
and heating B.B., the flame becomes green owing to the 
boron. 

Diff. The test for boron is good for all varieties. The 
dark generally are readily distinguished by the lustre, 
absence of distinct cleavage, and rather difficult fusibility. 
The black appear pitch-black on a surface of fracture, and 
have not the cleavage lines of surfaces characterizing prisms 
of hornblende. ‘The brown resemble garnet or idocrase, 
but are less fusible. The red, green, and yellow varieties 
are distinguished readily by the crystalline form, the prisms 
of tourmaline always having 3, 6, 9, or 12 prismatic sides 
(or some multiple of 8). ‘The electric properties of the 
crystals, when heated, is another remarkable character of 
this mineral. 

Obs. Common in granite, gneiss, mica schist, chlorite 
schist, steatite, quartzyte, and granular limestone; usually 
in crystals penetrating the rock. The black crystals are 
at times a foot long when perhaps of no larger dimensions 
than a pipe-stem, or even more slender. Has also been 
observed in sandstones near basaltic or trap dikes. Some- 
Pag penetrating quartz crystals in acicular crystals, like 
rutile. 

Red and green tourmalines, over an inch in diameter and 
transparent, have been obtained at Paris, Me., besides pink 
and biue crystals; fine also at Auburn, Hebron, Norway, 
Rumford, Andover, Me.; also, of much less beauty and size, 

* 20 


306 DESCRIPTIONS OF MINERALS. 


at Chesterfield and Goshen, Mass.; black at Norwich, New 
Braintree, and Carlisle, Mass.; Alsted, Acworth, and Sad- 
dleback Mountain, N. H.; Haddam and Monroe, Ct.; 
Pierpont, Saratoga, Port Henry, and Edenville, N. Y.; 
Franklin and Newton, N. J.; colorless and brown at 
Dekalb, N. Y.; transparent brown at Hunterstown, 
Canada; amber-colored, at Fitzroy; beautiful greenish yel- 
low, at G. Calumet I.; fine cinnamon-brown near Gouver- 
neur, Schroon, Canton, etc., northern N. Y.; Kingsbridge 
and Amity, Orange Co., N. Y.; and in Sussex Co., N. J.; 
gray, bluish gray, and green at Hdenville, N. Y.; yellowish, 
bluish, and brownish green at London Grove, and near 
Unionville, Pa.; black or dark brown, at Orford, N. H.; 
yellow in E. Marlboro’ and W. Marlboro’, Pa.; black at 
Leiperville and Marple, Pa.; thin black plates, in mica, at 
Grafton, N. H.; Franklin and Newton, Sussex Co., N. J. 

The word tourmaline is a corruption of the name used in 
Ceylon, whence it was first brought to Europe. Lyneurivum 
is supposed to be the ancient name for common tourmaline; 
and the red variety was probably called hyacinth. 

The red tourmalines, when transparent and free from 
cracks, are of great value and afford gems of remarkable 
beauty. They have the richness of color and lustre belong- 
ing to the ruby. The yellow tourmaline, from Ceylon, is 
hardly inferior to the real topaz, and is often sold for that 
gem. ‘The green specimens, when clear and fine, are also 
valuable for gems. Plates from pellucid crystals cut in the 
direction of a vertical plane are much used for polariscopes, 
and crystals in mica are often thus flattened and ready for 
such use when not too thin or opaque. 


Cappelenite. Yttrium-barium silico-borate, with 14:16 p. c. of 
silica; hexagonal; brown; G. = 4°4. Norway. 

Gehlenite. Tctragonal, like the scapolites in form; color grayish 
green to brown; G. = 2°9-3°07; formula Ca;A10,.Siz with some of 
the Al replaced by Ke, and some of the Ca by Fe and Mg. Silica 
about 30 per cent. Mount Monzoni, in the Fassa Valley. 


Andalusite. 


Orthorhombic; JA Z= 90° 48’. In prisms that are 
nearly square. Cleavage lateral; sometimes distinct. Also 
massive; indistinctly coarse columnar, never fine fibrous. 

Colors gray and flesh-red, pink. Lustre vitreous, or in- 


- SUBSILICATES. . 307 


clining to pearly. Translucent to opaque. Tough. H.= 
75. G. = 3°1-3°3. 





Composition. AlO,Si = Silica 36°9, alumina 63°1 = 100. 
B.B. infusible. Ignited after being moistened with cobalt 
nitrate assumes a blue color. Insoluble in acids. 

Chiastolite or Macle has an internal tessellated or cruci- 
form structure. Figures 1 to 4 represent sections of crystals 
from Lancaster, Mass. The structure is owing to carbona- 
ceous impurities distributed, in the crystallizing process, 
in a regular manner along the sides, edges and diagonals 
of the crystal. Mardness sometimes as low as 3. 

Diff. Distinguished from pyroxene, scapolite, spodumene, 
and feldspar by its infusibility, hardness, and form. 

Obs. Observed only in imbedded crystals. Most abundant 
in clay slate and mica slate, but occurring also in gneiss. 
The Tyrol; Saxony; Bavaria; etc.; also in Westford, Mass. ; 
Litchfield and Washington, Ct.; Bangor, Gorham, Standish, 
Me.; Leiperville, Marple, and Springfield, Pa., at Upper 
Providence, Pa., one crystal weighing 7 lbs.; as chiastolite 
at Sterling and Lancaster, Mass.; near Bellows Falls, Vt.; 
Chowchilla River, Mariposa Co., CaL First found at An- 
dalusia in Spain. 


Fibrolite—Sillimanite. Bucholzite. 


Orthorhombic; J A J= 96°-98°. In long, slender rhom- 
bic prisms, often much flattened, penetrating the gangue. 
Cleavage macrodiagonal, brilliant and easy. Also in 
masses, consisting of aggregated crystals or fibres. Color 
hair-brown or grayish brown. Lustre vitreous, inclining 
to pearly. ‘Translucent crystals break easily. H. = 6-7. 
G. = 3°2-3°3. 

Composition. AlO,Si, as for andalusite, = Silica 36°9, 
alumina 63°1= 100. Moistened with cobalt nitrate and 
sates assumes a blue color. Infusible alone and with 

orax. 

Diff. Distinguished from tremolite and the varieties gen- 
erally of hornblende by its brilliant diagonal cleavage, and 


308 DESCRIPTIONS OF MINERALS. 


its infusibility; from kyanite and andalusite by its brilliant 
cleavage, its fibrous structure, and its orthorhombic crys- 
talline form. 

Obs. Found in gneiss, mica schist, and rclated metamor- 
phic rocks. Occurs inthe Tyrol; at Bodenmais in Bavaria; 
at the White Mountain Notch in N. H.; at Chester and 
near Norwich, Ct., both in crystals, fibrous, and fibrous 
massive; Yorktown, N. Y.; Chester, Birmingham, Concord, 
Darby, Pa.; in N. Carolina; and elsewhere. Fibrolite was 
much used for stone implements in Western Europe in the 
«‘Stone age;” the locality whence the material was derived 
is not known. 


Davreuxite. Infusible. Probably impure fibrolite. 
Dumortierite. A related species, from near Lyons, 
Empholite. Infusible, and may belong here. Sweden. 


Cyanite.—Kyanite. Disthene. 


Triclinic. Usually in long thin-bladed crystals aggre- 
gated together, or penetrating the gangue. Sometimes in 
short and stout crystals. Lateral cleavage distinct. Some- 
times fine fibrous. 

Color usually light blue, sometimes having a blue centre 
with a white margin; sometimes white, gray, green, or even 
black. Lustre of flat face a little pearly. H. = 5-75, 
greatest at the ends of the prisms, and least on the flat face. 
G. = 3'55-3°7. 

Composition. AlO,Si (= AlO, + S10,), as for andalusite, 
= Silica 36:9, alumina 63°1= 100. Blowpipe characters 
like those of andalusite. 

Diff. Distinguished by its infusibility from varieties of 
the hornblende family. Short crystals have some resem- 
blance to staurolite, but their sides and terminations are 
usually irregular; they differ also in cleavage and lustre. 
The thin-bladed habit of cyanite is very characteristic. 

Obs. Found in gneiss and mica schist, and often accom- 
panied by garnet and staurolite. 

Occurs in long-bladed crystallizations at Chesterfield and 
Worthington, Mass.; at Litchfield and Washington, Ct.; 
Windham, Me.; Derby Creek, Delaware Co., and E. Brad- 
ford, Chester Co., Pa.; near Wilmington, Del.; and in Buck- 
ingham, and Spotsylvania cos., Va.; Chubb’s and Crowder’s 
Mts., Gaston Oo., N.C. Short crystals (sometimes called 


SUBSILICATES. 309 


improperly jidrolite) occur in gneiss at Bellows Falls, Vt., 
and at Westfield and Lancaster, Mass. 

In Europe, at St. Gothard in Switzerland; at Greiner and 
Pfitsch in the Tyrol; Styria; Carinthia; Bohemia. Villa Rica 
in §. America affords fine specimens. 

Named from the Greek kuwanos, a dark-blue substance. 
Also called Disthene, in allusion to the unequal hardness in 
different directions, and when white, Rhetizite. 

Kyanite is sometimes used as a gem, and has some re- 
semblance to sapphire. 


Topaz. 


Orthorhombic; 7A J=124° 17’, Rhombic prisms, usu- 
ally differently modified at the two extremities. Cleavage 
perfect parallel to the base. 

Color pale yellow; sometimes white, greenish, bluish, or 
reddish. Streak white. Lustre vitreous. ‘Transparent to 
subtranslucent. Pyro-electric. H.=8. G.3°4-3°65. 

Composition. AlO.Si, with a part of the oxygen replaced 
by fluorine = Silica 16:2, silicon fluoride 28:1, alumina 55:7 





= 100. An analysis of one specimen afforded Silica 34:24, 
alumina 57°45, fluorine 14°99. Including the fluorine, the 
formula is AlF,O,Si, I, replacing 1 of oxygen. B.B. infusi- 
ble; some kinds become yellow or of a pink tint when heated; 
moistened with cobalt nitrate and ignited assumes a fine 
blue color. Insoluble in acids. 

Diff. Readily distinguished from the minerals it resem- 
bles by its brilliant and easy basal cleavage. 

Obs. Pyenite has a thin columnar structure and forms 
masses imbedded in quartz. The Physalite or Pyrophysa- 
lite of Hisinger is a coarse, nearly opaque variety, found in 
yellowish-white crystals of considerable dimensions; intu- 
mesces when heated, and hence the name from phusao, to 
blow, and pur, fire. Topaz occurs altered to mica (da- 
mourite). | 


310 DESCRIPTIONS OF MINERALS, ~ 


Confined to metamorphic rocks or to veins intersecting 
them, and often associated with tourmaline, beryl, and oc- 
casionally with apatite, fluorite, and tin ore. 

Fine topazes are brought from the Uralian and Altai 
mountains, Siberia, and from Kamschatka, where they occur 
of green and blue colors. In Brazil they are found of a 
deep yellow color, either in veins or nests in lithomarge, or 
in loose crystals or pebbles. Sky-blue crystals have been 
obtained in the district of Cairngorm, in Aberdeenshire. 
The tin-mines of Schlackenwald, Zinnwald, and Ehren- 
friedersdorf in Bohemia, St. Michael’s Mount in Cornwall, 
etc., afford smaller crystals. The physalite variety occurs 
in crystals of immense size at Finbo, Sweden, in a granite 
quarry, and at Broddbo. A well-defined crystal from this 
locality, in the possession of the College of Mines of Stock- 
holm, weighs eighty pounds. Altenberg in Saxony is the 
principal locality of pycnite; it is there associated with 
quartz and mica. 

At Stoneham, Me., in fine crystals; Trumbull, Ct., in 
large coarse crystals, sometimes 6 to 7 in. through, and 
rarely small and transparent; Pike’s Peak, Col., in fine 
crystals, some affording cut stones 10 to 193 carats each ; 
also in Chalk Mt. and Nathrop, Col., in rhyolyte; in 
Utah, in rhyolyte, 40 m. N. of Sevier Lake; Arizona; Ore- 
gon, in gold-washings. 

The ancient topazion was found on an island in the Red 
Sea, which was often surrounded with fog, and therefore 
difficult to find. It was hence named from /opazd, to seek. 
This name, like most of the mineralogical terms of the an- 
cients, was applied to several distinct species. Pliny 
describes a statue of Arsinoé, the wife of Ptolemy Philadel- 
phus, four cubits high, which was made of topazion, or 
topaz, but evidently not the topaz of the present day, nor 
chrysolite, which has been supposed to be the ancient topaz. 
It has been conjectured that it was a jasper or agate; others 
have supposed it to be prase or chrysoprase. 

Topaz is employed in jewelry, and for this purpose its 
color is often altered artificially by heat. The variety from 
Brazil assumes a pink or red hue, so nearly resembling the 
Balas ruby, that it can only be distinguished by the facility 
with which it becomes electric by friction. Beautiful 
crystals for the lapidary are brought from Minas Novas, in 


SUBSILICATES. 311 


Brazil. From their peculiar limpidity, topaz pebbles are 
sometimes denominated gouttes deau. | 

On account of the perfect cleavage, topaz is a poor sub- 
stitute for emery. 


Evuclase. 


Monoclinic. In oblique rhombic prisms, with cleavage 
highly: perfect parallel to the clinodiagonal section, afford- 
ing smooth polished faces. 

Color pale green to white or colorless, pale blue. Lustre 
vitreous; transparent. Brittle H.=%7°5. G.=3°1. 
Pyro-electric. 

Composition.  H,3Be,Al10,,Si, = Silica 41°20, alumina 
35°22, glucina 17°39, water 6:19= 100. B.B. fuses with 
much difficulty to a white enamel; not acted on by acids. 

Diff. The cleavage of this glassy mineral is very perfect, 
like that of topaz, but is not basal. 

Obs. The Ural; Tyrol; with topaz in Brazil. 

The crystals are elegant gems of themselves, but are 
seldom cut for jewelry on account of their brittleness. 


Datolite.—Datholite. Humboldtite. 


Monoclinic; JA J=115° 3’. Crystals small and glassy, 
without distinct cleavage. . 

Also botryoidal, and columnar 
within (dotryolite); also mas- 
sive and porcelain-like in 
fracture. Color white, occa- 
sionally grayish, greenish, yel- 
lowish, or reddish. ‘Trans- 
lucent. ~ H. = 5-5°5. °G. = 
2°9-3. 

Composition. H,Ca,B,O,,8i, 
= Silica 37:5, boron trioxide 21°9, lime 35:0, water 5°6 = 
100. Botryolite contains twice the proportion of water. 
B.B. becomes opaque, intumesces and melts easily to a 
glassy globule coloring the flame green. Decomposed by 
hydrochloric acid; the solution gelatinizes on evaporation. 

Diff. Its glassy complex crystallizations, without cleay- 
age, distinguish it from other minerals that gelatinize with 
acid; so also its tingeing the blowpipe-flame green. 

Obs. Occurs in cavities in trap rocks, or the adjoining 
sandstone, and in gneiss. Found in Scotland; at Andreas- 





312 DESCRIPTIONS OF MINERALS. 


berg; Baveno; Toggiana. Also at Bergen Hill, N. J.; at 
Roaring Brook, 14 miles from New Haven; and near Hart- 
ford, Berlin, Middlefield Falls, Meriden, Tariffville, Ct.; 
in great abundance at Eagle Harbor in the copper region, 
Lake Superior, both in crystals and massive; on Isle Royale; 
near San Carlos, Cal. 


Homilite. A black silicate of iron and calcium, like datolite in its 
crystals; resembles gadolinite, but affords 15 to 18 per cent. of boracic 
acid with 82 of silica; formula R;:B.Oi0Siz. Brevig, Norway. 


Titanite.—Sphene. 
Monoclinic; J A £ = 118° 1’, 2A 2 = 136° 12’; crystals 
usually very oblique thin-edged prisms. Cleavage in one 


A oe 2. 


o 


direction sometimes perfect, owing to twin-composition. 
Occasionally massive. 

Color grayish brown, ash-gray, brown to black; some- 
times pale yellow to green. Streak uncolored. Lustre 
adamantine to resinous. ‘Transparent to opaque. H. = 
d-5'5. G, =3°4-3°56. 

Composition. CaTiO.Si = Silica 30°6, titanium dioxide 
40°82, lime 28°57 = 100; in dark brown and black crystals, 
some iron replaces part of the calcium. B.B. fuses with 
intumescence. Imperfectly decomposed by hydrochloric 
acid. 

The dark varieties of this species were formerly called 
titanete, and the lghter sphene. Named sphene from the 
wedge-shaped crystals, from the Greek sphen, wedge. 
Greenovite is a variety colored rose-red by manganese. 
Leucoxene and Titanomorphite are probably titanite(p. 453). 

Diff. The thin wedge-like form of the crystals is gener- 
ally a distinguishing character; but some crystals are of 
other forms. 

Obs. Occurs mostly in disseminated crystals in granite, 





9 


SUBSILICATES. 313 


gneiss, mica schist, syenyte, or granular limestone. Usually 
associated with pyroxene and scapolite, and often with 
graphite. Has been found in volcanic rocks. Crystals are 
commonly + to 4 an inch long; but sometimes very large. 

Foreign localities are Arendal in Norway; St. Gothard, 
Mont Blanc; Tyrol; Piedmont; Argyleshire and Galloway, 
Great Britain. Occurs at Roger’s Rock, on Lake George, 
_with graphite and pyroxene, at Gouverneur, near Natural 
Bridge in Lewis Co. (the variety called Lederite), in Mon- 
roe, Hdenville, Warwick, and Amity, in Orange Co., near 
Peekskill in Westchester County, and near West Farms, 
N. Y.; Lee, Bolton, and Pelham, Mass.; Trumbull, Ct.; 
Sanford and Thomaston, Me.; Franklin, N. J.; near Attle- 
boro’, Bucks Co., Pa.; at Dixon’s quarry, 7 miles from 
Wilmington, Del.; 25 miles from Baltimore, Md., on the 
Gunpowder; Renfrew, Canada, in enormous crystals, one 
weighing 72 pounds. 


Alshedite, from Sweden, is probably brown and gray titanite. 
Guarinite. Like sphene in composition, but orthorhombic. 
Keithauite, or Yttro-titanite. Related to sphene; brownish black, 
with a grayish brown powder; G. = 3°69; H.=65; fuses easily; 
affords Silica 30°0, titanic acid 29°0, yttria 9°6, lime 18°9, iron sesqui- 
oxide 6°4, alumina 6°1; also contains scandium. Arendal, Norway. 
Tscheffkinite, Near Keilhauite. Illmen Mountains. 


Staurolite.—Staurotide. 


Orthorhombic ; J A J= 129° 20’. Cleavage imperfect. 
Usually in cruciform twin crystals. 9. 
Figure 2, common; another crosses 
at an acute angle near 60°; another, 
of rare occurrence, consists of three 
crystals intersecting at angles near 
60°. Never in massive forms or 
slender crystallizations. 

Color brown to black. Lustre vitreous, inclining to 
resinous; sometimes bright, but often dull. Translucent 
to opaque. H. = 7-7°5. G. = 3:4-3°8; purest, 3°7-3°8. 

Composition. (4R,4Al),0,,Si,, in which R = iron with a 
little magnesium, and occasionally manganese, with some 
hydrogen of basic water. Silica 28°3, alumina 51°7, iron 
protoxide 15°8, magnesia 2°5, water 1°7= 100. B.B. in- 
fusible, excepting a manganesian variety. Insoluble in 
acids. : 





314 DESCRIPTIONS OF MINERALS. 


Diff. Distinguished from tourmaline and garnet by its 
infusibility and form. 

Obs. Found in crystals in mica schist and gneiss. 

Very abundant through the mica schist of New England: 
Grantham, Cabot, Windham, Me.; I'ranconia, Lisbon,. 
N. H.; Chesterfield, Mass.; Bolton, Tolland, Salisbury, 
Ct.; on the Wissahickon, 8 m. from Philadelphia; in 
Cherokee, Madison and Clay cos., N. C.; at Canton, and 
in Fannin Co., Ga., in handsome twins. Mt. Campione in 
Switzerland, and the Greiner Mountain, Tyrol, are noted 
foreign localities. 

Named staurolite from the Greek stawros, a cross. 


Schorlomite. Black, and often irised tarnished; streak grayish 
black; H. = 7-75; G. = 3°80; fuses readily on charcoal; easily de- 
composed by the acids, and gelatinizes; contains much titanium, with 
iron, lime, and silica. Magnet Cove, Ark.; Kaiserstuhlgebirge, 
Breisgau. Makes a black gem of submetallic lustre. 

Zunyite. In tetrahedrons, often transparent, and massive ; lustre’ 
vitreous; H. = 7; G. = 2°875; analysis afforded Silica 24°33, alum- 
ina 57°88, water (basic) 10°89, fluorine 5°61, chlorine 2°91, with a little 
FeO;, K.0, Na.O, Li,O. The Zufii Mine, San Juan Co., Col. 


B. HYDROUS SILICATES. 


The three sections under which the Hydrous Silicates 
are arranged are the following : 

I. GENERAL Section. Includes: (1) Bisilicates—Pec- 
tolite, Laumontite, Apophyllite, ete.; (2) Unisilicates— 
Prehnite, Calamine, etc.; and (3) Swbsilicates—as Allo- 
phane, and some related species. 

If. ZrorirE Section. Includes minerals which are 
feldspar-like in constituents, and apparently so in quantiv- 
alent (or oxygen) ratio; the basic elements being, as in the 
feldspars, (1) aluminium, and (2) the metals of the alkalies 
K, Na, and of the alkaline earths Ca, Ba, with also Sr, to 
the almost total exclusion of magnesium and iron. 

III. MARrGAROPHYLLITE SEcTION. Embraces species 
having a micaceous or thin-foliated structure when crystal- 
lized, with the surface of the folia pearly, and the plane 
angle of the base of the prism 120°. Whether crystallized 
or massive, the feel is greasy, at least when pulverized. 
It comprises (1) Bisilicates: including Tale and Pyrophyl- 
lite, which are atomically and physically similar species, 
although the former is a magnesium silicate, and the latter 


HYDROUS SILICATES—GENERAL SECTION. 315 


an aluminium silicate; (2) Non-alkaline Unisilicates, in- 
cluding Kaolinite and Serpentine, which have a similar 
difference in constituents to the preceding with the same 
likeness in composition, and, also, some related species; (3) 
Alkaline Unisilicates : as, Pinite and the Hydrous Micas, 
which are species containing potassium or sodium as an 
essential constituent; (4) the Chlorite Group, the species 
of which are mostly Subsilicates and non-alkaline, 


I. GENERAL SECTION. 
Pectolite. 


Monoclinic, isomorphous with wollastonite. Usually in 
ageregations of acicular crystals, or fibrous-massive, radiate, 
stellate. Color white, or grayish. Translucent to opaque. 
Tough, H.=5. G.= 2°86-2°88. 

Composition. RO,Si,in which R= 4H,1Na,4Ca, = Silica 
54°2, lime 33°8, soda 9°3, water 2°7=100. In the closed 
tube yields water. B.B. easily fusiblo. 41 ecomposed by 
hydrochloric acid, and the solution gcelatinizes on evapora- 
tion. 

Resembles fibrous varieties of tremolite, natrolite, thom- 
sonite, wollastonite. 

Obs. Occurs mostly in cavities or coams in trap or basic 
eruptive rocks, and occasionally in other rocks. Found 
at Ratho Quarry, Edinburgh, Scotland (fatholite, Walker- 
ite); at Kilsyth; Isle of Skye; the Tyrol; Bergon Hill, 
N. J.; compact at I. Royale, L. Superior, and near Point 
Barrow, Alaska. 

Okenite. Gyrolite. Related hydrous calcium silicates. Okenite is 
from the Farée Islands, Iceland, and Greenland, and gyrolite from 


the Isle of Skye, and from Nova Scotia 25 m. 8. W. of Cape Blomi- 
don. Zobermorite, from Isle of Mull, is near gyrolite. 


Laumontite. 


Monoclinic; 7A 7 = 86° 16’. Near pyroxene in form. 
Cleavage: clinodiagonal, and parallel to J, perfect. Also 
massive, with a radiating or divergent structure; not fine 
fibrous. 

Color white, passing into yellow or gray, sometimes red. 
Lustre vitreous, inclining to pearly on the cleavage face. 
Transparent to translucent. H. = 3°5-4. G. = 2:25-2°36. 
Becomes opaque on exposure through loss of water, and 
readily crumbles. 


316 DESCRIPTIONS OF MINERALS, 


Composition. CaAlO,,Si,-+4aq = Silica 50°0, alumina 
21°8, lime 11°9, water 16°3 = 100. B.B. swells up and fuses 
easily to a white enamel. Decomposed by hydrochloric 
acid, and the solution gelatinizes on evaporation. 

Diff. The alteration this species undergoes on exposure 
to the air at once distinguishes it. This result may be 
prevented with cabinet specimens by dipping them into a 
solution of gum-arabic. 

Obs. Found in the veins and cavities of trap-rocks and 
also in gneiss, porphyry. Occurs at the Farée Islands; Kil- 
patrick Hills, near Glasgow; Disco, Greenland; St. Gothard, 
Switzerland; Peter’s Point, N. Scotia; Phippsburg, Me.; 
Charlestown syenyte quarries, Mass.; Bergen Hill, N. J.; 
the Copper region, L. Superior, and Isle Royale. 

Leonhardite. Probably Laumontite which has lost part of its water 
by alteration—the part that goes off below 212° F. Resembles that 
species in crystallization and in most of its characters, but differs in 
being less cfflorescent on exposure to a dry atmosphere. Analyses of 
specimens from Copper Falls, Lake Superior, obtained, Silica 55°50, 
alumina 21°19, lime 10°56, water 11:93 = 99°68. The Copper Falls 


variety alters little on exposure. Reported also from trachyte at 
Schemnitz, Hungary; Pfitsch in the Tyrol. 


Apophyliite. 

Tetragonal. In square octahedrons, prisms, and tables. 
Cleavage parallel with the base highly perfect. Massive 
1 nis and foliated. Color white or 
® grayish; sometimes with a 
yp — 7 FES shade of green, yellow, or 
Clee : red. Lustre of O pearly: of 
the other faces vitreous. 
Transparent to opaque. H. 

2: = 45-5. G. = 2°3-2°4. 

f —_ 

rs flame violet (owing to the 
potash), and fuses very easily 
to a white enamel. In the closed tube yields water which 
has an acid reaction. Decomposed by hydrochloric acid 
with the separation of slimy silica. 


Composition. Silica 52°97, 
lime 24°72, potash 5°20, water 

Diff. The easy basal cleavage and basal pearly lustre, and 
the forms of its crystals, distinguish it from the preceding 


“. 





15:90, fluorine 2°10 = 100°89. 
B.B. exfoliates, colors the 


HYDROUS SILICATES—GENERAL SECTION. 317 


species. The prisms are sometimes almost cubes, with the 
angles cut off by the planes of the pyramid; but the differ- 
ence in the lustre of the prismatic and basal faces shows 
that it is tetragonal. It is never fibrous. 

The name alludes to its exfoliation before the blowpipe. 

Ods. Found in amygdaloidal trap and basalt. 

Fine crystallizations at Peter’s Point and Partridge 
Island, N. Scotia; Bergen Hill and Weehawken, N. J.; 
Cliff Mine, L. Superior region. 

Catapletite. Hydrous zirconium-sodium silicate. Norway. 

Dioptase and Chrysocolla. Hydrous copper silicates. See p. 156. 

Picrosmine, Pyratlolite, Picrophyll, Traversellite, Pitkaranadite, Stra- 
koniizite, Monradite, are names of varieties of pyroxene in different 
pees of alteration. Xyloiine and Pilolite are probably altered as- 

estus. 

Leidyite. A hydrous bisilicate of Al, Fe, Mg, Ca; in silky greenish 
scales. From Leiperville, Pa. 


Prehnite. 


Orthorhombic; J A J = 99° 56’. Cleavage basal. Some- 
times in six-sided prisms, rounded so as to be barrel-shaped, 
and looking as if made up of a series of united plates; also 
in thin rhombic or hexagonal plates. Usually reniform 
and botryoidal, with a crystalline surface. Never fibrous. 

Color apple-green to colorless. Lustre vitreous, except 
the face VU, which is somewhat pearly. Subtransparent to 
translucent. H. =6-6°5. G. = 2°8-2:96. 

Composition. H,Ca,A10,,8i, = Silica 43°6, alumina 24:9, 
lime 27°1, water 4.4 = 100. B.B. fuses very easily to an 
enamel-like glass. Decomposed by hydrochloric acid, leay- 
ing a residue of silica, but does not gelatinize. Yields a 
little water when heated in a closed tube. 

Diff. Distinguished from beryl, green quartz, and chalce- 
dony by fusing B.B., and from the zeolites by its hardness. 

Obs. Found in the cavities of trap, gneiss, and granite. 

Occurs in trap in the Connecticut Valley, and at Pater- 
son and Bergen Hill, N. J.; in gneiss at Bellows Falls, Vt.; 
in syenyte at Charlestown, Mass.; and very abundant, form- 
ing large veins, in the Copper region of Lake Stiperior, 
3 miles south of Cat Harbor, and elsewhere, where the green- 
ish variety called Chlorastrolite and Zonochlorite is found. 

The Fassa Valley in the Tyrol, St. Christophe in Dau- 
phiny, and the Salisbury Crag, near Edinburgh, are some 
of the foreign localities. | 


318 DESCRIPTIONS OF MINERALS. 


Prehnite receives a handsome polish, and is sometimes 
used for inlaid work. In China it is polished for orna- 
ments, and large slabs have been cut from masses brought 
from there. 


Gismondite (Zeagonite). A hydrous calcium-aluminium silicate, oc- 
curring in twinned crystals. Found in lava at Capo di Bove, near 
Rome; also near Gorlitz. 

Hdingtonite, Tetragonal; a hydrous barium-aluminium silicate. 
The Kilpatrick Hills, with harmotome. 

Carpholite. A manganese-aluminium silicate; in silky, yellow, radi- 
ated tufts. 'Tin-mines of Schlackenwald. 

Pitinite. A hydrous calcium-aluminium silicate; in fibrous felt- 
like crusts; B.B. fuses easily; insoluble in hot acid. Silesia. 

2 se co Hydrous magnesium silicate; gray; infusible. Wermland, 
weden. 

_ Pyrosmatite. A manganese-iron silicate and chloride. Sweden. 

| Calamine. A hydrous zinc unisilicate; see p. 174. 

Villarsite is probably altered chrysolite; see p. 277. . 

Cerite, T'ritomite, are cerium and lanthanum silicates. Thorite (Or- 
angite), Hucrasite, Hrdmannite, and Hreyalite are thorium silicates. : 
Kainosite, an yttrium, etc., silicate. 

Uranothorite. A thorite containing uranium; dark red-brown; in- 
fusible. Champlain iron region, Northern New York. 


Allophane. 


In amorphous incrustations, with a smooth small-mam- 
millary surface, and often hyalite-like, and sometimes pul- 
verulent. Color pale bluish white to greenish, and deep 
green; also brown, yellow, colorless. Translucent. H.=3. 
G. = 1°85-1°89. 

Composition. Mostly AlO,Si + 6 (or5)aq. Silica 23°75, 
alumina 40°62, water 35°63 = 100. In the closed tube 
yields much water. 8B.B. infusible, but crumbles. A 
blue color with cobalt solution, and a jelly with hydrochloric 
acid. 

Occurs in Saxony; a copper-mine in Bohemia; with lim- 
onite in Moravia; Chessy Copper Mine near Lyons; in Old 
Chalk Pits near Woolwich, England; with gibbsite in 
limonite beds in Richmond, Mass.; at the copper-mine of 
Bristol, Conn.; at Morgantown, Pa.; copper-mines of Polk 
County, Tenn.; Lawrence Co., Ind. 


Sulphatallophane, A mixture of allophane and a basic aluminium 
sulphate. 

Collyrite. A hydrous aluminium silicate containing only 14 to 15 
per cent. of silica, and 35 to 40 of water; and Schrditerite is another 
with 11 to 12 per cent. of silica. The latter has been reported as occur- 


HYDROUS SILICATES—ZEOLITE SECTION. 319: 


ring as a gum-like incrustation, at the falls of Little River, on Sand 
Mountain, Cherokee County, Alabama. Scarbdroiteis a related mineral 
of doubtful nature. 
Leucotile. A hydrous subsilicate. On serpentine. Silesia. 
Chaleomorphite. Hexagonal with basal cleavage; affords only 25:4 
p. c. of silica, with alumina, lime, and soda. Lake Laach; The Eiffel. 


II. ZEOLITE SECTION. 


The species of the Zeolite Section have been described as 
having some relation to the feldspars in constitution. In 
the feldspars, as explained on page 273, the following oxygen 
ratios, for the protoxides, alumina, and silica, are the com- 
momones: 123: 4,17 3:6; 1:3 38; 1:38:91: 3::10, 123 212: 
So, among the zeolites, if the water be left out of considera- 
tion, these are the ratios: 1:3: 4 (in Thomsonite), 1:3: 6 
(Natrolite, Scolecite, etc.), 1:3:8 (Analcite, Chabazite, 
etc.), 1:3: 10 (Harmotome), 1:3:12 (Stilbite, Heulandite, 
etc.). ‘This fact, added to the absence or nearly total ab- 
sence of magnesium and iron, and presence, instead, of Na.,, 
K,, Ca, Ba, make out a distinct relation to the feldspars, 
whatever may be the part which the water sustains in the 
compounds. JBesides barium, strontium is sometimes pres- 
ent, an element not yet known to characterize a species of 
feldspar. 

These minerals were called zeolites because they generally 
fuse easily with intumescence before the blowpipe, the term 
being derived from the Greek zeo, to boil. Among those 
described beyond, Heulandite and Stilbite have a strong 
pearly cleavage, and the latter is often in pearly radiations; 
Natrolite, Scolecite, are fibrous and radiated, or in very 
slender prisms; 'Thomsonite occurs either radiated, or com- 
pact, or in short crystals; while Harmotome, Analcite, and 
Chabazite, and the related Gmelinite, occur only in short 
or stout glassy crystals, those of chabazite looking some- 
times like cubes, and of analcite, like trapezohedral garnets 
in form. 

The zeolites are sometimes called ¢rap minerals, because 
they are often found in the cavities or fissures of amygda- 
loidal trap as well as related basic eruptive rocks. Yet 
they occur also occasionally in fissures or cavities in gneiss, 
granite, and other metamorphic rocks. They are not the 
original minerals of any of these rocks; but the results of 
alteration of portions of them near the little cavities or fis- 


320 DESCRIPTIONS OF MINERALS. 


sures in which the minerals occur; and part were made 
while the rock was still hot, and as cooling went forward. 
Besides true zeolites, such cavities often contain also 
Laumontite (p. 293), noted for its tendency to crumble on 
exposure; Pectolite and Okenite (p. 293), which are fibrous 
like Natrolite and Scolecite; Apophyllite (p. 294), having 
one pearly cleavage like heulandite and stilbite; Prehnite 
(p. 295), usually apple-green; Datolite (p. 289), in stoutish 
glassy complex crystals, or in smooth botryoidal forms; 
Aragonite (p. 218), sometimes radiated fibrous, and Calcite 
(p. 215) with its three directions of like easy cleavage, and 
effervescing with hydrochloric acid; Siderite (p. 185), in 
spheroidal or other forms; Chlorite (p. 316), granular mas- 
sive, of a dark olive-green color; and Quartz, either in 
crystals, or as chalcedony, agate, or carnelian, and in 
either case easily distinguished by the hardness, absence 
of cleavage, and infusibility. Of all these species Calcite 
and Quartz are the most common. Of rarer occurrence 
than the above, there are Orthoclase, Asphaltic coal, Cop- 
er, ete. 

: All the zeolites yield water in the closed tube, and many 
of them gelatinize with hydrochloric acid. 


Thomsonite. 


Orthorhombic; ZA J = 90° 26’. In right rectangular 
prisms. Usually in masses having a radiated structure 
within, and consisting of long fibres, or acicular crystals; 
also amorphous. Color snow-white; impure varieties 
brown. Lustre vitreous, inclining to pearly. ‘Transparent 
to translucent. H.=5-5. Brittle. G. = 2°3-2°4, 

Composition. (Ca, Na,)A1O,Si, + 23 aq = Silica 38°09, al- 
umina 31°62, lime 12°60, soda 4°62, water 13°40 = 100°20. 
B.B. fuses very easily to a white enamel. Decomposed by 
hydrochloric acid; solution gelatinizes on evaporation. 

Diff. Distinguished from natrolite by its fusion to an 
opaque and not to a glassy globule. 

Obs. Occurs in amygdaloid, near Kilpatrick, Scotland; 
at the Farée Ids. (Mesole or Faréelite) in spherical, lamellar 
radiated, and pearly within; in lavas at Vesuvius (Compton- 
ite); in clinkstone in Bohemia; the T'yrol, etc.; at Peter’s 
Point, Nova Scotia, in trap; a massive variety (Ozarkite) at 
Magnet Cove, Ark.; at Grand Marais, L. Superior, massive 


HYDROUS SILICATES—ZEOLITE SECTION. B ped 


and in hard nodules, radiated within, which have much 
beauty when polished, and are used in jewelry. 

The species was named after Dr. Thomas Thomson, of 
Glasgow. 


ITydronephelite. White; H. = 4.5; gelat. Litchfield, Me., from 
alteration of sodalite. 


Natrolite. 


mitpornombics JA; f= 91°; 1A 1 over x = 1487 20’. 
Prisms very slender and aggregated. Also in globular, 
stellated, and divergent groups of delicate 
acicular fibres, the fibres often terminating in 
acicular prismatic crystals. 

Color white, or inclining to yellow, gray, 
red. Lustre vitreous. ‘Transparent to trans- 
Iucent. HH. = 5-5°5. G. = 2°245-2°25. 
Brittle. 

Composition. Na,AlO,,Si, + 2 aq = Silica 
417-29, alumina 26°06, soda 16°30, water 9°45 
= 100. B.B. fuses easily and quietly to a clear glass; a 
fine splinter melts in a candle flame. Decomposed by hy- 
drochloric acid; the solution gelatinizes on evaporation. 

Diff. Distinguished from scolecite by its quiet fusion, 
and also by the characters mentioned below. 

Obs. Found in amygdaloidal trap, basalt and volcanic 
rocks; sometimes in seams in granitic rocks. Named from 
natron, soda. 

Occurs in Bohemia; Auvergne; Fassathal, Tyrol; at 
Glen Farg in Fifeshire; in Dumbartonshire; Nova Scotia; 
Bergen Hill and Weehawken, N. J.; Copper region, Lake 
Superior. 





Scolecite. Rescmblecs natrolite, and differs in containing /imein place 
of soda ; also in having its slender rhombic glassy prisms longitudi- 
nally twinned, as is shown by the meeting of two ranges of striex at an 
angle along or near the central line of opposite prismatic planes ; 
crystallization cither monoclinic or triclinic; lustre vitreous, or a little 
pearly; B.B. curls up like a worm (whence the name from the Greek 
skoléx, 2 worm) and then melts. Staffa; Farée; Iceland; Finland; 
Hindostan; Liguria; Fellinen Alp. 

Mevolite. A related species, similar in its acicular forms; monoclinic 
or triclinic. Includes Antrimolite and Harringtontie. Occurs on 
Faroe, at Giant’s Causeway, near Edinburgh, etc.; in N. Scotia at 
C. Blomidon. 

Pseudonatrolite, Resembles natrolite; fuses less easily, Elba, in 
granite. 


21 


822 -- DESCRIPTIONS OF MINERALS. 


Analcite. 
Isometric. Usually in trapezohedrons (Fig. 1, also Fig. 2). 

The appearance some- 
times seen in polarized light 
is Shown in Fig. 14, page 79. 
Often colorless and trans- 
parent; also milk - white, 
grayish and reddish white, 
and sometimesopaque. Lus- 
tre vitreous. H. = 5-55. 
G. =72225: 

Composition. Na,AlO,,Si, +2aq = Silica 54:47, alumina 
23°29, soda 14:07, water 8°17 = 100. B.B. fuses easily toa 
colorless glass. Decomposed by hydrochloric acid; the 
silica separates in gelatinous lumps. | 

Diff. Characterized by its crystallization, and absence of 
cleavage. Distinguished from quartz and leucite by giving 
water in a closed glass tube; from calcite by its fusibility, 
and by not effervescing with acids; from chabazite and its 
varieties by fusing without intumescence to a glassy globule, 
and by the crystalline form. 

Obs. Found in cavities and seams in amygdaloidal trap, 
basalt and other eruptive rocks, and sometimes in granite, 
syenyte, and gneiss. 

Occurs in fine crystallizations in Nova Scotia; also at 
Bergen Hill, N. J.; Perry, Me.; in the trap of the Cop- 
per region, Lake Superior; and near Montreal, Canada. 
The Farée Islands; Iceland; Glen Farg, near Edinburgh ; 
Kilmalcolm, the Campsie Hills, and Antrim; the Vicen- 
tine; the Hartz at Andreasberg; Sicily, and Vesuvius. 

The name analcite is from the Greek, analkis, weak, al- 
luding to its weak electric power when heated or rubbed. 





Hudnophite, Near analcite. Norway. 
faujasite. In isometric octahedrons, The Kaiserstuhl, Baden, 


Chabazite. 

Rhombohedral; R: R = 94° 46’. Often in rhombohed- 
rons, much resembling ‘cubes; also in complex 
twins. Cleavage parallel to 22. Never mssivae or 
fibrous. 

Color white; yellowish; flesh-red or red (Acadt- 
alite). Lustre vitreous. Transparent to trans 
lucent. H.=4-5. G, = 2:08-2°19. 


HYDROUS SILICATES—ZEOLITE SECTION. 323 


Composition. CaAlO,,Si, + 6 aq, witha little Na, or K, 
in place of part of the Ca. The Nova Scotia acadialite 
afforded Silica 52:20, alumina 18:27, lime 6°58, soda and 
potash 2°12, water 20°52. B.B. intumesces and fuses to a 
nearly opaque bead. Decomposed by hydrochloric acid, . 
with the separation of slimy silica. In the closed tube 
gives water. Phacolite is a variety in complex glassy 
crystals. ‘ 

Diff. The nearly cubical form often presented by the 
crystals of chabazite is a striking character. It is distin- 
guished from analcite as stated under that species; from 
calcite by its hardness and action with acids; from fluorite 
by its form and cleavage, and its showing no phosphores- 
cence. 

Obs. Found in trap and occasionally in gneiss, syenyte, 
and other rocks. From the Farée Ids.; Giant’s Causeway, 
Antrim; Isle of Skye; Bohemia (Phacolite); Poonah in 
India. The trap of Connecticut Valley, but in poor speci- 
mens; at Hadlyme and Stonington, Conn.; Charlestown, 
Mass.; Bergen Hill, N. J.; Piermont, N. Y.; Jones’s Falls, 
near Baltimore (Haydenite); fine in Nova Scotia, both 
white crystals, and also red (Acadialite) in abundance. 


TTerschelite. Near chabazite in form ; formula (+Na24Ca)AJO;,Si, + 
6 aq. Richmond, in Victoria, Australia; Sicily. 

Gimelinite, Closely resembles some chabazite, but its crystals are 
usually hexagonal rather than rhombohedral in appearance ; formula 
(Naz, Ca)AlO;.Si,; a Bergen Hill specimen afforded Silica 48°67, alu- 
mina 18°72, lime 2°60, soda 9°14, water 21°35 = 100-48; gelatinizes 
with hydrochloric acid, but in other respects resembles chabazite. 
Andreasberg; Antrim, Ireland; Skye; Bergen Hill, N. J.; Nova 
Scotia, at Cape Blomidon (Ledererite). Named after the chemist 
Gmelin. Groddeckite is a variety. 

Levynite (Levyne). Rbhombohedral, somewhat resembling gmelin- 
ite in its crystals; the water excluded, having the quantivalent ratio of 
labradorite, 1:3:6; colorless, white, grayish, reddish. Iceland; 
Greenland; Antrim; Londonderry; Hartfield Moss near Glasgow. 
Nanzed after the crystallographer, Lévy. 


Harmotome. 


Monoclinic. Unknown except in compound crystals; and 
commonly in forms similar to the annexed figure; also in 
compound rhombic prisms. 

Color white; sometimes gray, yellow, red, or brownish. 
aeauraueparent totranslucent. Lustre vitreous. H. = 4°5. 

tices A 85% 


324 DESCRIPTIONS OF MINERALS. 


Composition. BaAlO,,Si, + 5 aq = Silica 46°5, alumina 
15°9, baryta 23°7, water 13°9 = 100; but a little of the 
baryta replaced by potash. B.B. whitens, crumbles, and 
fuses quietly to a white translucent glass. Gives water in 
a closed glass tube. Partially decomposed by hydrochloric 
acid, and if sulphuric acid be added to the 
solution, a heavy white precipitate of 
barium sulphate is formed. Some varie- 
ties phosphoresce when heated. 

Diff. Its twin crystals, when distinct, 
cannot be mistaken for any other species 
except phillipsite. Much more fusible 
than glassy feldspar or scapolite; does not 
gelatinize like thomsonite. 

Obs. In amygdaloidal trap, and in 
trachyte and phonolyte; also in gneiss, and metalliferous 
veins. Iine at Strontian in Scotland (Morvenite), and in 
Dumbartonshire; Andreasberg in the Hartz; Kongsberg in 
Norway. Has been found in seams in the gneiss in the 
upper part of New York Island. 

Named harmotome from the Greek harmos, a joint, and 
temo, I cleave. 





Phillipsite. Near harmotome in its cruciform crystals and other 
characters, but differing in containing lime in place of baryta; differs 
also in gelatinizing with acids and in fusing with some intumescence; 
also occurs in sheaf-like aggregations and in radiated crystallizations, 
The Giant’s Causeway; Capo di Bove; Vesuvius; Sicily; Iceland. 

DBravaisite. Hydrous silicate of aluminium, potassium, maguesium 
and iron. Coal shales of Noyant, France, 


Stilbite. 


Monoclinic. In prisms like the figure, flattened parallel 
to the face 7-7, which is the direction of cleavage; 
1A 1= 119° 16’, and 114°. Also in sheaf-like 
aggregations, and spheres, thin pearly lamellar- 
columnar in structure; also in radiated crystal- 
lizations; never fine fibrous. 

Color white; sometimes yellow, brown, or red. 
Subtransparent to translucent. Lustre highly 
pearly on cleavage surface. H. = 3-5-4. G, = 2-1-2:15. 

Composition. CaAlO,,Si,-+ 6 aq = Silica 57-4, alumina 
16°5, lime 89, water 17°2 = 100; but with a little Na, or K, 
in place of part of the Ca. 3B.B. exfoliates, swells up, and 





HYDROUS SILICATES—ZEOLITE SECTION. BRO 


curves into fan-like forms, and fuses to a white enamel. 
Decomposed by hydrochloric acid without gelatinizing. 

Diff. Cannot be scratched with the thumb-nail, like gyp- 
sum. Unlike heulandite in its crystals. 

Obs. Occurs mostly in trap or basaltic rocks; also on 
eneiss and granite. Found on the Farée Ids. ; Isle of Skye; 
Isle of Arran, and elsewhere, Scotland ; Andreasberg, Hartz ; 
the Vendayah Mts., Hindostan. Sound sparingly at the 
Chester and Charlestown syenyte quarries, Mass. ; at New 
Haven, Thatchersville and Hadlyme, Ct., and other points 
in the Connecticut Valley trap; at Phillipstown, N. Y.; 
Bergen Hill, N.J.; in the copper region of Lake Superior; 
in beautiful crystallizations at various points in Nova Scotia. 

The variety in spheres (spherostilbite) occurs in I. Skye; 
Elba; in the U. States, in T'yringham, Mass.; in N. Scotia. 

Named stilbite from the Greek s¢i/bé lustre. Has also 
been called Desmine, and in Germany Heulandite, where 
heulandite has been called séilbite. 


Foresite. From Elba, in minute crystals on tourmaline. 


Heulandite. 


Monoclinic. In right rhomboidal prisms like the figure, 
with perfect pearly cleavage parallel to P, and other 
planes vitreous in lustre. PAMorT= 90°; MAT 
=129° 40’. Color white; sometimes reddish, gray, 
brown. ‘Transparent to subtranslucent. Folia brit- \ 


tere i, — 370-4. GG. = 2°2. 
Composition. CaAlO,Si,+5 aq = Silica 59:1, alu- ie 


= 


mina 16°9, lime 9°22, water 14:°8=100. Contains 

1 to 2 per cent. of Na, or K, in place of part of the 

Ca. Blowpipe characters like those of stilbite. In- 
tumesces and fuses, and becomes phosphorescent. Dis- 
solves in acid without gelatinizing. 

Diff. The very pearly lustre of the cleavage face is a 
marked characteristic. Distinguished from gypsum by its 
hardness; from apophyllite and stilbite by its crystals; and 
from the latter species also in not occurring in radiated, 
sheaf-like or spherical crystallizations. 

Obs. Found in cavities and fissures in trap; occasionally 
in gneiss, and in some metalliferous veins; in large crystal- 
lizations at Berufiord, Iceland; and Vendayah Mts., Hin- 
dostan ; also at Isle Skye; near Glasgow; Fassa Valley; 


326 DESCRIPTIONS OF MINERALS. 


Elba (Oryzife); at Bergen Hill, N. J., in trap; at Had- 
lyme, Ct., and Chester, Mass., on gneiss; Leiperville, Pa. ; 
near Baltimore, on hornblende schist (Senta at 
Peter’s Point and Cape Blomidon, and other places in Nova 
Scotia, in trap. 

Named by Brooke after Mr. Heuland, of London. 

Brewsterite. Crystals monoclinic, with a perfect pearly cleavage 
like heulandite; but MAT = 93° 40'; H.=43-5; G.= 2°48; for- 
mula analogous to that of heulandite, but baryta and strontia take 
the place of the lime and soda. Strontian, Argyleshire ; Antrim ; 


Mont Blanc ; near Baréges, Pyrenees. 

Epistilbite. Composition like that of heulandite, but occurs in short 
and very obtuse monoclinic rhombic prisms (AJ = 185° 10’). Skye; 
the Farée Ids. ; Iceland ; Poonah, India ; Margarctville, Nova Scotia. - 
Parastilbite and Reissite are referred here. 

Mordenite. Fibrous silky concretions. Morden, Nova Scotia. 
Steeleite is partially altered mordenite. 


Ill. MARGAROPHYLLITE SECTION. 
Talc. 


Orthorhombic; JA J = 120°. In right rhombic or hex- 
* agonal prisms. Usually in pearly foliated masses, separat- 
ing easily into thin translucent pearly folia. Sometimes 
stellate, or divergent, consisting of radiating lamine. Often 
massive, consisting of minute pearly scales; also crystalline 
granular; also cryptocrystalline. 

Lustre eminently pearly, and feel greasy. Color some 
shade of light green or greenish white; occasionally silvery 
or pearl white; also grayish green and dark olive-green. 
H. = 1-1°5; easily impressed with the nail. G. = 2°5-2°8. 
Lamine flexible, but not elastic. 

Varieties. Soliated Tale. White to greenish white. 

Soapstone or Steatite. White, gray, grayish green; 
either massive, crystalline granular, or impalpable; greasy 
to the touch. French chalk isa milk-white variety, with 
a pearly lustre. Potstone or Lapis Ollaris is impure soap- 
stone of grayish green and dark green colors. 

indurated Tale. A slaty tale, of compact texture, and 
above the usual hardness, owing to impurities. 

Rensselaerite. A compact cryptocrystalline rock, from 
St. Lawrence and Jefferson cos., N. Y., white, yellow, 
grayish white, to brown and black. Has sometimes the 
form and cleavage of pyroxene, and is in part at least a prod- 


HYDROUS SILICATES—MARGAROPHYLLITE SECTION. 327 


uct of the alteration of that mineral. Part of Pyradlolite 
belongs here. 

Composition. 1H,4Mg¢0,Si = Silica 62°8, magnesia 33°5, 
water 3°7 = 100. Usually contains a little iron replacing 
magnesium. B.B. infusible; after moistening with cobalt 
nitrate a pink tint; in closed tube gives a little water, but 
not till highly heated. Not acted upon by hydrochloric acid. 

Diff. The extreme softness, greasy feel, foliated struct- 
ure, when crystallized, and pearly lustre of talc are good 
characteristics. Differs from mica also in being inelastic, 
although flexible; from chlorite, kaolinite, and serpentine 
in yielding little water when heated in a glass tube. Only 
the massive varieties resemble the last-mentioned species, 
and chlorite has a dark olive-green color. Pyrophyllite, 
which cannot be distinguished, in some of its varieties, by 
the eye alone, from talc, becomes dark blue when moistened 
with cobalt nitrate and ignited. 

Obs. Occurs in Cornwall, near Lizard Point; at Portsoy 

in Scotland; at Croky Head, Ireland; in the Greiner 
Mountain, Saltzburg. Handsome foliated talc occurs at 
Bridgewater, Vt.; Smithfield, R. I.; Dexter, Me.; Lock- 
wood, Newton, and Sparta, N. J., and Amity, N. Y.; 
Staten Island, near the Quarantine, both the common and 
indurated; at Cooptown, Md., green, blue, and rose-colored; 
in Georgia. Steatite or soapstone is abundant, and is 
quarried at Grafton, Cambridgeport, Chester, Perkinsville, 
Saxton’s River, Vt.; at Francestown, Orford, Weare, War- 
ner, Richmond, Haverhill, N. H.; at Middlefield, Mass. ; 
in Loudon Co., Va., and at many other places. 

Tale is ground up and used largely for adulterating soap, 
and to some extent in the manufacture of paper. 

Soapstone is sawn into slabs and used for linings of fur- 
naces, stoves and fire-places, etc.; made into images in 
China, and into inkstands and other forms in other coun- 
tries; ground up for use in lubricating machinery, and the 
inside of a tight boot; worked into vessels for culinary pur- 
poses in Lombardy. Soapstone is also used in the manu- 
facture of porcelain; it makes the biscuit semi-transparent, 
but brittle and apt to break with slight changes of heat. It 
oy ae a polishing material for serpentine, alabaster, and 
glass. 


328 DESCRIPTIONS OF MINERALS. 


Pyrophyllite.—Agalmatolite, in part. 


Near talc in crystallization, cleavage, its occurrence in 
both thin foliated and fine-grained massive forms, its greasy 
feel, its white to pale green colors, varying to yellowish, its 
feeble degree of hardness (1-2). ‘The folia are sometimes 
radiated. G. = 2°75-2°92. 

Composition. An aluminous bisilicate, instead of a mag- 
nesian, mostly of the formula, AlO,Si,. The Chesterfield, 
S. C., mineral afforded Genth, Silica 64°82, alumina 24°48, 
iron sesquioxide 0°96, magnesia 0°33, lime 0°55, water 5°25 
= 100°39. B.B. whitens and fuses with difficulty on the 
edges; a deep blue color with cobalt solution; yields water 
in the closed tube. Radiated varieties exfoliate in fan-like 
forms. 

Obs. Compact pyrophyllite is the chief constituent of a 
kind of slate or schist, which has been used for slate pen- 
cils, and hence is called pencil-stone. Occurs in the Urals; 
at Westana in Sweden; in Elfdalen, with cyanite; foliated, 
in N. Carolina, in Cottonstone Mountain ; Chesterfield 
District, 8. C., with lazulite and cyanite; Lincoln Co., Ga., 
on Graves Mountain; near Little Rock, Ark.; compact 
slaty in the Deep River region, N. C., and at Carbonton, 
Moore County, N. C. 


Sepiolite.—Meerschaum of the Germans. 


Usually compact, of a fine earthy texture, with a smooth 
feel, and white or whitish color; also fibrous, white to bluish 
green in color, H. = 2-2°5. The earthy variety floats on 
water. 

Composition. 4H,2Mg0,Si-+ 13 aq = Silica 60°8, magnesia 
27-1, water 12°1= 100. B.B. infusible, or fuses with great 
difficulty on the thin edges. Much water in a closed tube. 
A pink color with cobalt solution. 

Occurs in Asia Minor in masses in stratified earthy de- 
posits, and extensively used for pipe-bowls; also found in 
Greece, Moravia, Spain, etc.; also in fibrous seams at a sil- 
ver mine in Utah. 


Bis Aphrodite. Similar tothe preceding. Mg0O;Si+ 3H. From Swe- 


Cimolite. A clay from the Island of Argentiera, Kimole of the Greeks; 
Richmond, N. 8. W. 

Smectite. A kind of ‘‘ Fuller’s Earth,” a name given to unctuous clays 
used in fulling cloth. 


HYDROUS SILICATES—MARGAROPHYLLITE SECTION. 329 


Montmorillonite. Rose-red to white, bluish; soft and tender; a hy- 
drous aluminium silicate. Montmorillon, France; Cornwall; Branch- 
ville, Ct. Stolpenite, Confolensite, Delanouite, Steargillite, the Sapo- 
nite of Plombiéres, are related to this species. 


Glauconite.—Grecen Earth. 


In dark olive-green to yellowish green grains, or granular 
Mineees, with dull-lustre. H.=2. G. = 2°2-2°4. 

Composition. Essentially a silicate of iron and potassium. 
Formula RRO,,Si, + 3 aq, in which Ris mainly Feand K,, 
and Ris Al, but sometimes largely Fe. Analyses give 
mostly 50-58 per cent. silica, 20-24 iron protoxide, 4-12 of 
potash, and 8-12 of water. B.B. fuses easily to a mag- 
netic glass. Yields water in a closed tube. 

Obs. Mixed with more or less sand, it forms thick 
beds called “‘green sand” in the Cretaceous formation, and 
also in the Lower Tertiary; also occurs in other older rock 
formations down to the Lower Silurian. Found also, first 
by Pourtales, in the pores of corals and cavities of Rhizopod 
shells over the existing sea-bottom, showing it to be a ma- 
rine product, and one now in progress of formation. The 
grains of the Cretaceous, Tertiary, and Lower Silurian beds 
were shown first by Ehrenberg to be the casts of the inte- 
rior of shells of Rhizopods. ‘The silica has been supposed 
to come from the siliceous secretions of a minute sponge 
growing in the cavities that afterward became occupied by 
the glauconite. Abundant in New Jersey a few miles north, 
east and south of Freehold. 

Bravaisite. Gray to greenish; H. = 1-2; feel greasy. Near glau- 
conite. 

Celadonite. A green earth with 53 per cent. of silica, from amygda- 
loid, near Verona; Scotland. Probably an impure chlorite. 

Chloropal. Massive; somewhat opal-like in appearance; greenish 
yellow to pistachio-green; consists chiefly of silica, iron sesquioxide, 
and water. Wontronite, Pinguite, Unghwarite, and Gramenite are 
varieties of it. Unghwar, Hungary; Nontron, France; near Gottingen; 
Bohemia; Mudgee, N. 8. W. 

Stilpnomelane. Foliated and also fibrous, or as a velvety coating; 
black to brownish and yellowish bronze in color and Instre; G. = 5- 
3°4; chiefly silica and iron oxides, with 8 to 9 per cent. of water. 


Chalcoditz, in velvety coatings at the Sterling Iron Mine, Antwerp, 
Jefferson Co., N. Y., is here included. 


Serpentine. 


Usualiy massive and compact in texture; also lamellar or 
foliated, the folia brittle; also columnar, asbestiform, and 


330 DESCRIPTIONS OF MINERALS. 


delicately silky fibrous. Often in crystals pseudomorphous 
after chrysolite and some other species. Color light to dark 
oil-ereen, to olive-green and blackish green; also greenish 
yellow, brownish yellow, brownish red; rarely white. Lus- 
tre weak; resinous, sa CMBINE to greasy. Translucent to 
nearly opaque. H.= 2°5-4, G. = 2°5-2°6. Feel, espe- 
cially of powder, a little greasy. ‘Tough. Fracture con- 
choidal. 

Composition. A hydrous magnesium silicate, like talc, but 
containing more water and less silica. H,Mg,O0,Si,-+ laq = 
Silica 43°48, magnesia 43°48, water 13-04= 100. B.B. 
fuses with much difficulty on ‘thin edges. Yields water in 
the closed tube. Decomposed by hydrochloric acid, leaving 
a residue of silica. In some kinds iron replaces part of the 
magnesium. 

Specimens of a rich oil-green color, and translucent, are 
called precious serpentine, and the “nearly opaque kinds 
common serpentine. Chrysotile is fibrous serpentine; it in- 
cludes Amianthus and part of Asbestus. Unlike true as- 
bestus, it affords much water in aclosed tube. Meéetazxite, 
Picrolite, and Baltimorite are coarse fibrous kinds. A thin 
foliated variety, from Hoboken, N. J., was named Marmo- 
lite, before it was known to be serpentine; Antigorite and 
Williamsite are coarse foliated varieties; efdanskite con- 
tains nickel. A porcelain-like serpentine—the Meerschaum 
of Taberg and Sala—has been called Porcellophite; and a 
resin-like variety, Retinalite and Vorhauseritte. Mixed with 
limestone it makes a green clouded marble called Verd-an- 
tigue and Ophiolite. 

Diff. The distinguishing characters of the compact min- 
eral are no cleavage, feeble lustre, slightly waxy or oily lus- 
tre, little hardness, being so soft as to be easily cut with a 
knife, yielding much water, and specific gravity not over 
2°65. 

Cbs. Named from its green color, which is often clouded, 
serpent-like. Common as a rock as well as an imbedded 
mineral. It has been made through the alteration of an- 
hydrous magnesian silicates, as chrysolite, pyroxene, ensta- 
tite, hypersthene, tremolite, actinolite, chlorite, chondrodite, 
and others. Chrysolite is the most common source. Some 

basaltic and other eruptive rocks consisting largely of pyr- 
oxene and chrysolite have been changed to impure serpen- 
tine. Foliated chlorite has given origin to some foliated 


HYDROUS SILICATES—MARGAROPHYLLITE SECTION. 331 


serpentine, as probably that of marmolite; and cleavable 
pyroxene to the partially altered foliated kinds called Bastite, 
Schiller-spar, and Antillite. Pelhamite is an asbestiform 
serpentine material made by alteration. The white marble 
of Essex Co., N. Y., dotted with green serpentine, a ‘‘ verd- 
antique,” was once dotted probably with pyroxene; and 
other verd-antiques have had a similar origin. The serpen- 
tine of New Rochelle, N. Y., was made in part from ensta- 
tite and.tremolite or actinolite; and that of Brewster, N. Y., 
part of which is white, from chondrodite, chlorite, enstatite, 
and to a small extent from biotite and dolomite. The 
**« Kozoon,” consisting of delicate layers of serpentine and 
calcite, is regarded by some as serpentine of mineral origin, 
which became cracked from drying while it was in a semi- 
gelatinous state, and which then had the delicate cracks 
filled by calcite. 

Serpentine occurs in Cornwall; near Portsoy in Aberdeen- 
shire; in Corsica, Siberia, Saxony, Norway, Silesia, etc. 

In the United States it occurs at Phillipstown, Port 
Henry, Gouverneur, Warwick, New Rochelle, Rye, Staten 
Island, N. Y.; Newburyport, Westfield, Blandford, Mass. ; 
Kellyvale, New Fane, Vt.; Deer Isle, Me.; New Haven, 
Ct.; Bare Hills, Md.; Hoboken, N. J.; Brewster’s, Put- 
nam Co., N. Y.; Texas and elsewhere, Pa.; in N. Carolina; 
over large areas N. and 8S. of San Francisco, Cal.; Canada, 
at Orford, Ham, Bolton, etc. 

Serpentine when polished has much beauty, especially 
when constituting a verd-antiqgue marble. Chromic iron 
or magnetite is usually disseminated through it, and in- 
creases the variety of its colors. It occurs near Milford 
and New Haven, Ct.; Port Henry, Essex Co., N. Y., and 
elsewhere. Pennsylvania serpentine is used as a building- 
stone in Philadelphia. 

The asbestus of this species is used like hornblende as- 
bestus, and largely obtained for the trade at Staten Island, 
in Canada, and in Italy. But it is an inferior kind, owing 
to the 14 pounds of water present to every hundred of the’ 
pure material, which a high heat will drive off and, if it is 
confined, may do it explosively. 


Bowenite. Has the composition of serpentine, but the hardness 
5°5-6, and the aspect of nephrite, with G.= 2°59-2°8, Smithfield, R. I. 


332 DESCRIPTIONS OF MINERALS. ~ 


Deweylite. 


Massive. Color whitish, yellowish, brownish yellow, 
greenish, reddish. Has the aspect of gum-arabic or a 
resin. Very brittle. H.=2-3°5. G.=1°9-2°25. 

Composition. Near serpentine, but containing 20 per 
cent. of water. 

Obs. From Middlefield, Mass.; Bare Hills, Md. (Gym- 
qite); Texas, Pa.; the Fleims Valley, Tyrol. 


Cerolite. Related to deweylite; from Silesia. Zimbachite from 
Limbach, and Zéblitzite from Zéblitz, are similar. 

Hydrophite, Like deweylite, but containing iron in place of part 
of the magnesium. Taberg in Smaoland. 

Jenkinsite is a fibrous varicty of hydrophite occurring on mag- 
netite at O’Neil’s mine, in Orange Co., 

Genthite or Nickel- gymnile. Similar to deweylite, but containing 
much nickel ; analysis affording Silica 35°36, nickel protoxide 30°64, 
iron protoxide 0°24, magnesia 14: 60, lime 0 26, water 19°09 = 100°19; 
G.=2°4. Texas, Pa.: ; Webster, N. C.; Michipicoten Island, Lake 
Superior ; Malaga, Spain ; Saasthal, Upper Valois.  Réttisite is 
similar, 


Saponite. 


Soft, clay-like, of the consistence, before drying, of 
cheese or butter, but brittle when dry. Color white, yel- 
lowish, grayish green, bluish, reddish. Does not adhere 
to the tongue. 

Composition. A hydrous silicate of magnesia containing 
some alumina. 

From Lizard’s Point, Cornwall, in serpentine. Also 
from geodes of datolite, Roaring Brook, Ct.; in trap, north 
shore of Lake Superior. 


Kaolinite. 


Orthorhombic; JA J=120°. Massive, clay-like, but 
consisting often of thin, microscopic, rhombic or hexagonal 
crystals; ‘either compact, friable, or mealy. Feels greasy. 
Color white, grayish white, yellowish, sometimes brownish, 
bluish, or reddish. Scales flexible, inelastic. H.=1-2 5, 
ae 2-4-2 °6. 

Composition. H,A10,Si, + laq = Silica 46:4, alumina 
39°7, water 13°9 = 100. The similarity of the composition 
to that of serpentine will be seen on comparing the two 
formulas. B.B. infusible. A blue color with cobalt solution. 
Yields water in the closed tube. Insoluble in acids, 


HYDROUS SILICATES—MARGAROPHYLLITE SECTION. 333 


Obs. The soapy feel of kaolinite distinguishes a clay con- 
sisting of it or containing much of it; when common clays are 
*‘ unctuous” it is usually owing to the presence of kaolinite. 
Kaolinite has been made through the decomposition of 
aluminous minerals, and especially feldspars, but mostly 
from the potash feldspar, orthoclase. In the case of these 
feidspars the process (1) removes the alkalies; (2) leaves 
the alumina, or a large part of it, and part of the silica; 
and (3) adds water. So that orthoclase, K,Al10,,S:, loses 
K, and part of the Siand O, and becomes changed to H,AlO, 
Si, +1 aq; half the water which is added replaces K, which 
is removed. Many granites, gneisses, and feldspar-bearing 
quartzytes undergo rapidly this change, so that extensive 
beds of kaolinite have been formed and are now making in 
many regions. ‘This result is promoted by the action of 
the carbonic acid of rain and other waters, which removes 
the alkali; also by that of the organic acids which the de- 
composition of plants or animals contribute to such waters. 
The kaolinite is usually washed out by flowing waters from 
the decomposed material to make the large pure deposits. 
The New Jersey clay-beds of the Cretaceous formation and 
those of Long Island, N. Y., are mainly kaolinite. A pure 
kaolinite bed occurs at Brandon, Vt., along with a limo- 
nite bed; a much larger at Clayton in New Marlboro’, Mass.; 
also in Delaware and Chester cos., Pa.; at King’s Mtn., 
S. C.; also in other States. Most of the limonite beds of 
Eastern N. America afford some kaolinite; yet it is gen- 
erally more or less colored by iron oxide. 

Common clays consist of powdered feldspar, quartz, and 
other mineral material, with more or less kaolinite. They 
burn red in case they contain iron in the state ordinarily 
present in them of iron carbonate, or hydrous iron oxide 
(limonite), or in combination with an organic acid, or in 
some other alterable state of composition, heat driving off 
the carbonic acid or water, or destroying the organic acid, 
and so leaving the red oxide of iron (or sesquioxide), or 
favoring its production. But the iron may be so combined ~ 
as not to give the red color; and this has been found to be 
true with the clays from which the cream-colored Milwau- 
kee (Wisconsin) brick are made, and that of other clay 
beds in that vicinity. The iron may be there in the state 
of the silicate, zoisite; or it may form this mineral, or one 
allied to it, in the kiln. When clay consists in part of 


334 DESCRIPTIONS OF MINERALS. 


powdered feidspar, it is more or less fusible and unfit for 
making fire-bricks. 

Pure kaolinite (or kaolin as it is ordinarily called) is 
used in making the finest porcelain. For this purpose it is 
mixed with pulverized feldspar and quartz, in the propor- 
tion needed to give, on baking, that slight incipient degree 
of fusion which renders porcelain translucent. The name 
kaolin is a corruption of the Chinese word Kauling, mean- 
ing high ridge, the name of a hill near Jauchau-Fu, where 
the mineral is obtained; and the etuntze (peh-tun-tsz) of 
the Chinese, with which the kaolin is mixed in China for 
the manufacture of porcelain, is, according to 8. W. Wil- 
liams, a quartzose feldspathic rock, consisting largely of 
quartz. ‘The word porcelain was first given to China-ware 
by the Portuguese, from its resemblance to certain sea- 
shells ealled Porcellana ; they supposed it to be made from 
shells, fish-glue, and fish-scales (‘S. W. Williams). . 

The white clays are used for stoneware, fire-bricks, re- 
torts for gas-works, sewer-pipes, etc.; and the pure kaolin 
extensively for giving body and weight to paper. 


Pinite. 

Amorphous, and usually cryptocrystallme; but often 
having the form of the crystals of other minerals from the 
alteration of whichit has been made. Colors grayish, green- 
ish, brownish, and sometimes reddish. Lustre feeble; waxy. 
Translucent to opaque. H. = 2°5-3'5, G. = 2°6-2°73 
some, 2°85. 

Composition. Mostly (H,K),Al,0,,Si,. The pinite of 
Saxony afforded Silica 46°83, alumina 27°65, iron sesqui- 
oxide 8°71, magnesia 1°02, lime 0°49, soda 0°40, potash 
6°52, water 3°83 = 99°42; and, in another analysis, potash 
10°74. Ithas in part the physical characters of serpentine; 
but, at the same time, it has nearly the composition of a 
hydrous potash mica. Some of it has been proved to con- 
sist of very minute scales that are mica, and it is inferred 
that pinite may usually be a massive form of hydrous mus- 
covite. 

Obs. 'The varieties are in general pseudomorphs after 
different minerals, and hence comes a part of their varia- 
tions in composition. ‘They include Pinite, from the 
Pini Mine, near Schneeberg and elsewhere; uiescckite, 
pseudomorph after nephelite from Greenland, and from 


HYDROMICA GROUP. 313) 3) 


Diana, N. Y.; Avllinite, formed from spodumene, at Kil- 
liney Bay, Ireland, Branchville, Ct., and Chesterfield, 
Mass.; Dysyntribite, from Diana, N. Y., identical with 
gieseckite; Pinitotd, from Saxony; Wilsonite, from Bath- 
urst, Canada, having the cleavage of scapolite; Terenite, 
from Antwerp, N. Y., like Wilsonite; <Agalmatolite, or 
Pagodite, from China, being one of the materials for carv- 
ing into images, ornaments, models of pagodas, etc.; Gi- 
gantolite and J/berite, which have the form of iolite. A 
variety from Elba was formed from andalusite. 


Polyargite, Rosite, Cataspilite, Biharite, Giimbelite, Rauite, Restor- 
melite, are related materials. 

Pholerite, Halloysite, Severite, Glagerite, Lenzinite, Bole, Lithomarge, 
are names of clay-like minerals. 

Palagonite. The material of some tufas, and the result of change 
through the agency of steam or hot water at the time, probably, of the 
deposition of the material ; a mixture, and not a true mineral. Tufas 
of Iceland, Sicily, etc. Named from Palagonia, Sicily. 


HYDROMICA GROUP. 3s 

The following species are mica-like in cleavage and aspect, 
but talc-like in wanting elasticity, in greasy feel, and in 
pearly lustre. They are sometimes brittle. Common mica, 
muscovite, readily becomes hydrated on exposure; but 
hydrous micas are not all a result of alteration. Hydromica 
schists form extensive rock-formations, equal to those of the 
ordinary mica schists. ‘They were for the most part called 
Talcose slate (or Talk-schiefer in German) from their greasy 
feel, until the fact was ascertained that they contained no 
magnesia: a point demonstrated for the Taconic slates of 
the western border of Massachusetts, by C. Dewey, in 1819, 
and later, by G. I’. Barker, for those of Vermont. . 


Margarodite. Damourite. WHydrous micas related to muscovite, 
which see (p. 288). Parophite is a hydromica schist from Pownal, 
Vt., and Stanstead, Canada. Sericite and sericite schist are hydromica 
schist from near Wicsbaden and elsewhere. 

Groppite. A rose-red to brownish red foliated mineral from Gropp- 
torp, Sweden. 

Huphyltite. Mica-like; folia rather brittle; lustre pearly, white or 
colorless; contains much sodium; an analysis afforded Silica 41°6, 
alumina 42°3, lime 1°5, potash 3°2, soda 5:9, water 5°55 = 100. Occurs 
with corundum at Unionville, Delaware County, Pa. 

Cookeite. In minute mica-like scales, and in slender six-sided 
prisms; affords only 2°57 of potash, with 2°82 of lithia; the water 


336 DESCRIPTIONS OF MINERALS. 


13°41 per cent. On crystals of red tourmaline, at Hebron and Paris, 
Me., having been formed through their alteration. Named after Prof. 
J. P. Cooke, of Cambridge, Mass. 

Voigtite. The mica of a granite at Ehrenberg, near IImenau, which 
has the composition of biotite, plus 9 per cent. of water. 

Roscoelite. A vanadium-mica of dari brownish green color, occur- 
ring in micaceous scales, and affording over 20 per cent. of vanadium 
oxides, along with 47°69 of silica, 14:10 of alumina, 7°59 of potash, 
4°96 of water, and a little magnesia and soda. Probably a mixture. 
From Granite Creek Gold Mine, El Dorado County, California. 


Fahlunite. 


In six and twelve-sided prisms, usually foliated parallel 
to the base, but owing the prismatic form to the mineral 
from which it was derived. Folia soft and brittle, of a 
hes green to dark olive-green color, and pearly lustre. 

ame 

Composition. A hydrous silicate of aluminium and iron 
with little or no alkali, and in this last point differing from 
pinite. An average specimen afforded Silica 44°60, alumina 
30°10, iron protoxide 3°86, manganese protoxide 2°24, mag- 
nesia 6°75, lime 1°35, potash 1°98, water 9°35 = 100°23. 
B.B. fuses to a white glass. In a closed tube gives water. 
Insoluble in acids. 

Diff. It is distinguished from tale by affording much 
water before the blowpipe, and readily by its association 
with iolite, and its large hexagonal forms, with brittle folia. 

Qbs. Fahlunite has been derived from the alteration of 
iolite. The quantivalent ratio of iolite for the protoxides, 
sesquioxides, and silica is 1: 3:5; and for fahlunite, the 
same, with 1 for the water, making the whole 1:3:5:1. 
The hydration appears to go on at the ordinary temperature, 
and in some localities all the iolite to a considerable depth 
in the rock is changed to fahlunite. There are different 
varieties, depending on the amount of water, and tne con- 
ditions under which the change has taken place. The 
names they have received are Hydrous Jolite, Chlorophyliite, 
Esmarkite, Aspasiolite, Pyrargillite, Triclasite. Fahlunite 
was so named from its locality, Fahlun, Sweden; and Ch/o- 
rophyllite from its greenish color and foliated structure, the 
specimens to which it was given occurring at Unity, N. H. 
Haddam, Ct., is anotker locality. Gigantolite and Iberite 
are also altered iolite, but they contain potash, and belong 
hence to the Pinite Group. . 


CHLORITE GROUP. 337 


Venasquiie. Resembles ottrelite; lamellar; grayish-black. In 
analysis, Silica 44°79, alumina 29°71, iron protoxide 20°75, magnesia 
0°62, water 4°93 = 100°80; oxygenratio1:3:6:10. From Vénasque, 
Pyrenees. 

Mrinite. A bright blue earthy mixture. From the Pyrenees, 


CHLORITE GROUP. 


The chlorite group includes the hydrous Swdsilicates of 
the Margarophyllite Section and also some related species 
that are Unisilicates. ‘The proportion of silica is small, the 
percentage afforded by analyses being under 38, and mostly 
under 30, ‘The minerals when well crystallized are foliated 
like the micas, and have the plane angle of the base of the 
crystals 120°, but the folia are inelastic and in some species 
brittle. They also occur in fibrous and in fine granular and 
compact forms, and the latter are usually most common. 
Green, varying from light to blackish green, is the prevail- 
ing color, yet gray, yellowish, reddish, and even white and 
black also occur; and the colored transparent or translu- 
cent are dichroic. The green color is owing to the presence 
of iron, and fails only in species containing little or none 
of it. All of the species yield water in a closed tube. 
The quantivalent (or combining) ratio for R+ R and Si is, 
in the 


Pyrosclerite subdivision.......... Sd by 
Chlorite subdivision.............. si on ae a Ge 
Chloritoid subdivision.... ...... 1:4tol1: 4. 


The chlorite subdivision includes Penninite, Ripidolite, 
and Prochlorite, together with some related dark green to 
blackish green species. Some species of this subdivision 
characterize extensive rock-formations, making chlorite 
schist or slate; and they give rise also to chloritic varieties 
of other rocks. Moreover, chlorite is a result of the altera- 
tion of pyroxene, hornblende, and some other iron-bearing 
minerals; and pyroxenic igneous rocks, like basalt, are 
often strongly chloritic (as revealed by the microscopic 
examination of thin transparent slices), in consequence of 
this alteration—but alteration that took place before the 
rock had cooled. Such green chloritic material, where the 
species is not determinable, has been called Viridite. The 
cavities in amygdaloid are often lined, and sometimes filled, 
by a species of chlorite, which was made from certain con- 

22 


338 DESCRIPTIONS OF MINERALS, 


stituents of the amygdaloid in the manner just stated; and 
the rocks adjoining trap-dikes are at times penetrated by 
chlorite made in them by means of the heat, and the mois- 
ture contained in them or ascending with the erupted rock. 


Hisingerite. 


Massive; reniform. Color black to brownish black. Streak 
yellowish brown. Lustre greasy, inclining to vitreous. H. = 
3B, "Ge 8 °045: i 

Composition. A hydrous iron silicate, (H,2Fe),0,,Si, 
+4aq = Silica 35°9, iron sesquioxide 42°6, water 21°5 = 100. 
In some analyses part of the iron is in the protoxide state. 
B.B. fuses with difficulty to a magnetic slag. 

Obs. From Sweden; Norway; Finland. Scotiolite and 
Degeroite are referred here. Afelanolite, from Milk-Row 
quarry, near Charlestown, Mass., is related in composition, 
if the material analyzed was a pure species. 

Gillingite, from Sweden (including Thraulite from Bavaria), Lillite. 
Other hydrous silicates of iron. 

Hkmannite. Foliated, chlorite-like; a hydrous iron silicate, but the 
iron mostly in the protoxide state. Sweden in the rifts of magnetite. 

Lpichlorite. Between chlorite and schiller spar; a hydrous silicate 
of aluminium, iron, and magnesium, Altered bronzite? In serpen- 
tine at Harzburg. 

Neotocite (Stratopeite) and Witlingite are results of the alteration of 
ae and contain manganese. Stiibelite also contains manganese 
oxide. ° 

Strigovite from Striegau, Jollyte from Bodenmais, Hullite from 


Ireland, are hydrous silicates of aluminium and iron, with little mag- 
nesium. 


Pyrosclerite. 


Orthorhombic or monoclinic. Mica-like in cleavage; folia 
flexible, not elastic. Color apple-green to emerald-green. 
Lustre pearly. H.=3. G.= 2°74. 

Composition. (3Mg,+Al),0,,8i, +3 aq = Silica 38:9, 
alumina 14:8, magnesia 34°6, water 11°7 = 100. B.B. fuses 
to a grayish glass; gelatinizes with hydrochloric acid. 

Obs. Occurs in serpentine, on Elba. 

Chonicrite (Metazotte). Related to the above in composition, but 
affords 12 to 18 per cent. of lime. | 


Vermiculite. 


Mica-like in cleavage. In aggregated scales. Also in 
large micaceous crystals or plates. Lamine flexible, not 


CHLORITE GROUP. 339 


elastic. Color gray, brown, yellowish brown. Lustre 
pearly. . 

Composition. Mg, (#e, Al) O,,Si,. Exfoliates when 
heated, and when scaly-granular the scales open out into 
worm-like forms; and thence the name, from the Latin 
vermiculor, to breed worms; B.B. fuses finally to a gray 
mass. rom Milbury, Mass. 


Jefferisite is a similar mineral in composition and exfoliation, occur- 
ring in broad folia; composition $Mg,4(Fe, Al)O,.Si3. In serpen- 
tine in Westchester, Pa. Oulsageeite from Culsagee, North Carolina; 
Hallite from Lerni, Delaware Co., Pa.; Protovermiculite from Magnet 
Cove, Ark.; Philadelphite, from Philadelphia, Pa., are other micaceous 
hydrous unisilicates, similar to vermiculite and jefferisite in exfolia- 
tion. Kerrite and Maconite are reiated to the above; they are from 
Franklin, Macon Co., North Carolina. The quality of exfoliating is 
due to the water present, and is produced in some mica by alteration. 
It is a question how far these vermiculite-like species are alteration 
products. 


Penninite.—Chlorite in part. Pennine. 


Rhombohedral. Cleavage basal and highly perfect, mica- 
like. Also massive, consisting of an aggregation of scales, 
and cryptocrystalline. Color green of various shades; also 
yellowish to silver-white, and rose-red to violet. Lustre 
pearly on cleavage surface. Transparent to translucent. 
Lamine flexible, not elastic. H. = 2-2°5, 3 on edges. 
G. = 2°6-2°75. 

Composition. A specimen from Zermatt, in the Pennine 
Alps, afforded Silica 33°64, alumina 10°64, iron sesquioxide 
8°83, magnesia 34°95, water 12°40 = 100°46. The rose-red, 
from Texas, Pa., gave Silica 33°20, alumina 11°11, chro- 
mium oxide 6°85, iron sesquioxide 1°43, magnesia 35°54, 
water 12°95, lithia and soda 0°28, potash 0°10 = 101-46. 
Other Texas specimens afforded 0°90 to 4°78 per cent. of 
chromium oxide. B.B. exfoliates somewhat and fuses with 
difficulty. Partially decomposed by hydrochloric acid, and 
wholly so by sulphuric acid. 

From Zermatt, Ala in Piedmont, the Tyrol, ete. <Adm- 
mererite, Ihodochrome, and Rhodophyllite include the red- 
dish variety from near Miask, Russia; Texas, Pa.; ete. 
Pseudomorphs after hornblende, named Loganite, have the 
composition of this species; and so has the massive mineral 
called Pseudophite aud Allophite. paler 


340 DESCRIPTIONS OF MINERALS. 


Delessite. A fibrous chlorite like mineral near the above in compo- 
sition. From amygdaloid at Oberstcin. 

Huralite. An amorphous chlorite, near Penninite. From Eura, 
Finland; in amygdaloid. 

Diabantite (Diabantochronyn). A chlorite from amygdaloid. A 
Farmington (Conn.) specimen afforded Hawes, Silica 33°68, alumina 
10°84, iron sesquioxide 2°86, iron protoxide 24°33, MnO and CaO 
1:11, magnesia 16°52, soda 0°38, water 1002 = 99°69. Steatargiilite 
contains much iron. 

Chloropheiie. A doubtful chlorite. Amygdaloid, in Scotland. 


Ripidolite.—Chlorite, in part. 


Monoclinic. Similar in cleavage and mica-like character 
to penninite, and also in its colors, lustre, hardness, and 
specific gravity. 

Composition. A specimen from Chester Co., Pennsylvania, 
afforded Silica 31°34, alumina 17°47, chromium sesquioxide 
1°69, iron sesquioxide 3°85, magnesia 33°44, water 12°60 = 
100°39. B.B. and with acids nearly like penninite. <A va- 
riety from Willimantic, Ct., exfoliates like vermiculite and 
jefferisite. 

Kotschubeile is a red variety from the Urals. Clinochlore 
and Grastite are here included. Occurs at Achmatovsk 
and elsewhere in the Urals; at Ala, Piedmont; at Zermatt; 
Westchester, Unionville and Texas, Pa.; Brewster’s, N. Y. 


Prochlorite.—Chlorite in part. 


Hexagonal. Similar in cleavage and mica-like characters 
to the preceding. Color green to blackish green; some- 
times red across the axis by transmitted light. G. =2°75-3. 
Lamine not elastic. 

Composition. A specimen from St. Gothard afforded Sili- 
ca 25°36, alumina 18°56, iron protoxide 28°79, magnesia 
17:09, water 8:96 = 98°70; and a North Carolina specimen, 
Silica 24°90, alumina 21°77, iron sesquioxide 4°60, iron 
protoxide 24°21, manganese protoxide 1:15, magnesia 12°78, 
water 1059 = 100. B.B. same as for preceding. 

Lophoite, Ogcoite, Helminthe belong here. Occurs at St. 
Gothard; Greiner in the Tyrol; Traversella. in Piedmont, 
a other places in Kurope. Also at Steele’s Mine, 


Leuchtenbergite. A prochjorite with the base almost pe? ine 
sium. Rubdisiite is a doubtful chlorite. . 


CHLORITE GROUP. 341 


Aphrosiderite, Near prochlorite in composition. Weilburg, Ger- 
many. 

Venerite. A pale green earthy chlorite-like material containing 
copper. Berks Co., Pa. 

Corundophilite. Near prochlorite. With corundum at Asheville, 
N. C.; Chester, Mass. Amestte. 

Grochauite. From Grochau in Silesia. 

Cronstedtite. Hexagonal, with perfect basal cleavage; black; G. = 
8°35; consists mainly of silica, iron oxides, and water, with a little 
manganese oxide. Bohemia; Cornwall. 

Qhuringite. Another hydrous iron silicate; G. = 3°15-8°20; dark 
green to yellow-green. Thuringia; Hot Springs, Arkansas; near 
Harper’s Ferry, on the Potomac; Unionville, Pa. (Paitersonite). 


Margarite.—Emerylite. Diphanite. Clingmanite. Corundellite. 


Orthorhombic. JFoliated, mica-like. Laminz rather 
brittle. Color white, grayish, reddish. Lustre of cleay- 
age surface strong pearly and brilliant, of sides of crystals 
vitreous. H. = 3°5-4°5. G. = 2°99. : 

Composition. H,RAI,O,,Si, = Silica 30-1, alumina 51:2, 
lime 11°6, soda 2°6, water 4°5—= 100. B.B. whitens and 
fuses on the edges. 

Obs. Often associated with corundum and diaspore. Oc- 
curs in Asia Minor; at Sterzing in the Tyrol; in the Urals; 
in Village Green and Unionville, Pa.; Buncombe County, 
N. C.; Chester, Mass. Named from the Greek margarites, 
a pearl. 


Willcoxite. Near margarite. 
Dudleyite. An alteration product of margarite. 


Chloritoid.—Masonite. Phyllite. Ottrelite. 


Monoclinic. Cleavage basal, perfect, Also coarse foli- 
ated massive; and in thin disseminated scales (phyllite or 
ottrelite). Brittle. 

Color dark gray, greenish. to black. Lustre of cleavage 
surface somewhat pearly. H. = 55-6. G. = 3°5-3°6. 

Composition. KeAlO,Si + 1 aq = Silica 24:0, alumina 
40-5, iron protoxide 28:4, water 7-1 = 100. B.B. becomes 
darker and magnetic, but fuses with difficulty. Decomposed 
completely by sulphuric acid. 

Obs. Found at Kossoibrod, Urals, with cyanite; in Asia 
Minor, with emery; at St. Marcel (Sismondine); Ottrez, 
France (Otirelite); Chester, Mass.; in Rhode Island (Ma- 


842 DESCRIPTIONS OF MINERALS. 


sonite); at Brome and Leeds, Canada; in scales (Phyllite) 
characterizing the ‘‘ spangled mica slate” of Newport, R. I., 
and Sterling, Goshen, etc., Mass. 


Seybertite (Clintonite). Monoclinic. Thin foliated; somewhat mica- 
like; basal cleavage perfect; lamine brittle; color reddish or yellowish 
brown to copper-red; lustre pearly submetallic. H. = 4°5. G. =38. 
Analysis by Brush obtained Silica 20°24, alumina 39°13, iron sesqui- 
oxide 3°27, magnesia 20°84, lime 13°69, water 1:04, potash and soda 
1°48, zirconia 0°75 = 100°39, giving the quantivalent ratio for protox- 
ides, sesquioxides, silica, and water 6:9:5:4. Amity, N. Y.; Sia- 
toust, Urals (Xanthophyllite, Waluewite); Fassa Valley (Brandisite and 
Disterrite). 


3. HYDROCARBON COMPOUNDS. 


The following are the subdivisions here used: 

I. StmptE Hyprocarsons: Marsh-gas, Mineral oils, and 
Mineral wax. ; 

II. OxyGENATED HYDROCARBONS: mostly resins. 

III. ASPHALTUM AND MINERAL COALS. 


I. SIMPLE HYDROCARBONS. 
Marsh-Gas.—Light See at aaa Rock Gas. Natural 
as. 


Colorless and inodorous when pure, burning with a yel- 
‘oy tame. and consisting of Carbon 75, hydrogen 25 = 100 
= BE BY 

Natural gas varies in composition according to its source, 
the marsh-gas being mixed with more or less of nitrogen, 
carbonic acid (CO,), and some other ingredients. That 
which occurs bubbling up in marshes, as a result of the de- 
composition of organic matters and accompanying deoxi- 
dation of the atmosphere, often contains much nitrogen; 
Websky finding the composition in one case: Marsh-gas 
43°36, nitrogen 53°67, CO, 2°97 = 100. The CO, is in small 
amount, although an abundant product of decomposition, 
because it enters into combinations with earthy bases pres- 
ent, and is to some.extent soluble in water. | aetite 

The natural gas from deeper sources, arising occasionally 
through springs, and obtained by borings, such as is now 
used extensively for lighting and heating, is chiefly pure 
marsh-gas, with often 2 or 3.p. c. of nitrogen, as much 


SIMPLE HYDROCARBONS, 843 


sometimes of carbonic acid, a little free hydrogen, and occa- 
sionally very sparingly other gaseous products of the marsh» 
gas series. ‘The gas of a well of Butler Co., Pa., afforded 
marsh-gas 80°11, hydrogen 13°50, carbonic acid 0: 66, ethane 
5°72 = 99°99; and that of the Kare well, Findlay, Ohio, 
marsh-gas 92° 61, hydrogen 2:18, olefiant gas 0°30, nitrogen 
3°61, oxygen 0:34, CO, 0°50, CO 0: 26, sulphuretted hydro- 
gen 0: 20; but the nitrogen is sometimes in large propor- 
tions, up to 25 or 30 per cent. Moreover, the same gas- 
well gives a varying gas, one in western Pennsylv ania afford- 
ing marsh-gas 57°85 per cent., hydrogen 9°64, nitrogen 
23°41 on the 18th of October, 1884; the corresponding 
numbers 75°16, 14°45, 2°89 on the 25th: and 72°18, 20:02, 
0:00, on the 28th, 

The districts affording natural gas are usually those af- 
fording also more or less mineral oil, the gas and oil being 
related carbohydrogen compounds, and the latter yield- 
ing the former. ‘The strata below are but slightly dis- 
turbed, that is, have very gentle pitch if any, and are un- 
crystalline. Deep below the surface there are blackish 
carbonaceous shales, slates or limestones, or other de- 
posits of the kinds that yield mineral oil and gas when 
heated. The gas, like the mineral oil, is supposed to 
be usually confined in very porous coarse sandstones, and 
not in open cavities; these porous strata being situated 
above the gas-yielding stratum. ‘The gas may have been 
made through the action of low heat on the blackish car- 
bonaceous rocks (slight disturbances having occasioned the 
heat required). 

i Beds of buried vegetation occur in the drift of Ohio and 

the States west, and have been the source of some marsh- 
gas, ‘ sufficient for domestic use.” But the large discharges 
of gas in the United States are from older deposits from the 
Tertiary to the Lower Silurian, and come from borings to 
depths often of 1000 to 2000 feet or more. The wells of 
Northwestern Ohio (about Findlay) go down to the Trenton 
limestone; but most of those of Western Pennsylvania and 
the regions adjoining stop in the Subcarboniferous or De- 
vonian. Black shales are widely distributed over the globe, 
and the supply may be long continued, although becoming 
locally exhausted in a short period. 

Natural gas was first used for lighting in Fredonia, Erie 
Co., N. Y., where it is given out from springs. In 1872 


344 DESCRIPTIONS OF MINERALS. 


and 1873 the waste gas of the petroleum-wells of Butler 
and Crawford cos., Pa., began to be used for heating 
boilers and lighting. In 1882 wells were sunk in Western 
Pennsylvania to obtain gas, and since then natural gas has 
become in some localities in different States almost the sole 
fuel and lighting material for large cities and villages, with 
all their factories. ven Eastern New York, at Knowers- 
ville, has a gas-well; and borings are beginning to be pro- 
ductive in the Western States and Territories. ‘The gas is 
lit up and put out in an instant, gives a steady heat, needs 
no attention, makes no ashes, requires no storage of fuel, 
burns without odor, and yields no sulphur to injure fur- 
naces and products of manufacture, etc. 

In the Murraysville district—one of those supplying 
Pittsburg—the best wells afford 10,000,000 to 33,000,000 
of cubic feet of gas per day. ‘The pressure at the source is 
commonly 200 to 800 pounds to the square inch, but in 
some cases 500 to 700 pounds. In the shallow wells of 
other regions (and some deep wells) the pressure is often 
but 50 pounds or less. 

With gas of average composition, 1000 cubic feet have, 
theoretically. the heating power of about 54°4 pounds of bi- 
tuminous coal and 58°4 of anthracite (S. A. Ford), so that 
41,000 ft. of gas are equivalent to 2240 pounds, or a ton, of 
coal. ‘It is safe to adopt a practical equivalence of 30,000 
cubic feet of gas to 1 ton of coal” (J. P. Lesley). 

The first use of natural gas for lighting and heating was 
in China. In the province of Sz’chuen are artesian wells 
1500 to 3000 feet deep, yielding brines, oil, and abundant gas. 
The gas is conveyed in bamboos and used for evaporating 
the brines and lighting. Jn the petroleum region of Baku, 
on the Caspian, are ‘‘ eternal fires” of similar origin. All 
regions of mineral oil probably have stored gas below. 


Petroleum. 


Mineral oils, varying in density from 0°60 to 0°85. Solu- 
ble in benzine or camphene. ‘They consist chiefly of liquids 
of the Naphtha and Hthylene series. ‘The composition of 
the Naphtha or Marsh-gas series is expressed by the general 
formula, OC,H,,-+2, of which Marsh-gas is the first or 
lowest term; and that of the Ethylene series by the for- 
mula, C,H,, = Carbon 85°71, hydrogen 14:29=100. The 


SIMPLE HYDROCARBONS. 345 


oils vary greatly in density from the lightest naphtha, too 
inflammable for use in lighting, to thick viscid fluids; and 
thence they pass by insensible gradations into asphaltum or 
solid bitumen. ‘The Marsh-gas series contains also gases, 
of the composition C,H, and C,H, and these, in addition 
to Marsh-gas, often exist in connection with petroleum. 

Petroleum occurs in rocks of all ages, from the Lower 
Silurian to the most recent; in limestones, porous or com- 
pact sandstones, and shales; but it is mostly obtained from 
cavities existing among the earth’s strata or more probably 
from the porous strata themselves. Black shales and much 
bituminous coal afford it abundantly when they are heated; 
but the oil obtained is not present in these rocks, for when 
the rocks are treated with benzine, the benzine takes up 
little or none; instead, the rocks contain an insoluble hydro- 
carbon, which yields the oil when heat is applied. 

In the United States the oil, or the hydrocarbon which 
yields it, has been observed in beds of the Lower and Upper 
Silurian, Devonian, Carboniferous, Triassic, Cretaceous, and 
Tertiary eras. Surface oil-springs also occur in many places. 
Foreign regions noted for mineral oil are Rangoon in Bur- 
mah, where there are about 100 wells; at Baku on the Cas- 
pian, whose springs promise to supply Russia and Europe 
with petroleum. Pliny mentions the oil spring of Agrigen- 
tum, Sicily, and says that the liquid was collected and used 
for burning in lamps, as a substitute for oil. Moreover he 
distinguishes the oil from the lighter and more combustible 
naphtha, a locality of which about the sources of the Indus, 
‘‘in Parthia,” he mentions. 

Petroleum is obtained chiefly at the present time from 
porous oil ‘‘ sands” (coarse sandstones), or cavities between 
or within the rock strata, reached by boring. Being under 
pressure from the gas associated with it, and also, in many 
cases, that of water, it rises to the surface in the boring, and 
sometimes makes a ‘‘spouting” well. As early as 1833, 
Hildreth mentioned the discharge of oil with the waters 
of the salt wells of the Little Kanawha Valley, and speaks 
also of a well near Marietta, Ohio, which threw out at one 
time, he says, 50 to 60 gallons of oil at ‘‘ each eruption.” 
The great oil-districts of Pennsylvania are the Venango in 
the western part, and the Bradford in the northern (McKean 
Co.), which extends 5 m. beyond the New York boundary. 
Oil is also obtained in Ohio, 25 m. N. of Zanesville, and 


346 DESCRIPTIONS OF MINERALS. 


in Kentucky and West Virginia, but not abundantly. 
There are also productive wells in California in the San 
Fernando district, Los Angeles Co., and in Ventura Co. 
There are also wells in Colorado and Wyoming. ie 

The mineral oil of the rocks has been formed through 
the decomposition of animal and vegetable substances. 
From the nature of the shales which most abound in the 
species of hydrocarbons that yield oil, it is evident that 
the rock material of the shales was in the state of a fine 
mud; that through this mud much vegetable or animal 
matter-was distributed, almost in the condition of an emul- 
sion; that the stratum of mud becoming afterward over- 
laid by other strata, the decomposition of vegetable or 
animal matter went forward without the presence of atmo- 
spheric air, or with only very little of it. Under such cir- 
cumstances either vegetable material or animal oils might 
be converted, as chemists have shown, into mineral oil. 
Dry wood consists approximately (excluding the ash and 
nitrogen) of 6 atoms of carbon to 9 of hydrogen, and 4 of 
oxygen. If now all the oxygen of the wood combines with 
a part of the carbon to form carbonic acid, and this 2C0,, 
thus made, is removed, there will be left C,H,; twice this, 
C.H,,, is the formula of a compound of the Marsh-gas or 
Naphtha series. Again animal oils, by decomposition under 
similar circumstances, produce like results. Removing from 
oleic acid its oxygen, O,, and 1 of carbon—the two together 
equivalent to 1 of carbonic acid—there is left C,,H,,, which 
is an oil of the Ethylene series. So margaric acid would 
leave, in the same way, C,,H,,, or a combination of oils of 
the Marsh-gas or Naphtha series. Warren and Storer have 
obtained from the destructive distillation of a fish-oil, after 
its saponification by lime, several compounds of the Marsh- 
gas series, besides others of the Ethylene and Benzole series. 
The decompositions in nature may not have been as simple 
as those in the above illustrations, yet the facts warrant the 
inference that the oils may have been derived either from 
vegetable or animal matters. fossil fishes are often found 
abundantly in black oil-yielding shales, and Dr. Newberry 
has suggested that fish-oil may be the most abundant source 
of the oil and the oil-yielding hydrocarbons. 

The oil which is collected in porous sandstones or cavities 
among the strata, as in Western Pennsylvania, is believed by 
most writers on the subject to have come from underlying 


SIMPLE HYDROCARBONS. 3847 


rocks, such as the black oil-yielding shales. The heat pro- 
duced in the rocks by the friction attending movements and 
uplifts is supposed to have been sufficient to have made the 
oil from the hydrocarbon of the carbonaceous shale or other 
rock, and to have caused it to ascend among the strata to 
the cavities or porous ‘‘ sands” where it was condensed, 
and now is found by boring. 

The oils, exposed to the air and wind, undergo change in 
three ways. J?rst: the lighter naphthas evaporate, leaving 
the denser oils behind, and, ultimately, the viscid bitumens; 
or else parafiin, according as paraftin is present or not in 
the native oil. At the naphtha island of T'schelekan, in 
Persia, there are large quantities of Neft-gil, as it is called, 
which is nearly pure paraffin. The hot climate of the Cas- 
pian is favorable for such a result. Secondly: there may 
be a loss of hydrogen from its combination with the oxygen 
of the atmosphere to form water, which escapes. Thus the 
oils of the Naphtha series may change into those of the 
Hthylene or Benzole series. Zhirdly: there may be an 
oxidation of the hydrocarbon of the oils, producing asphal- 
tum or more coal-like substances, like albertite. 

The word naphtha is from the Persian, nafata, to exude; 
and petroleum from the Greek, petros, rock, and the Latin, 
oleum, oil. 


Hatchettite.—Mountain Tallow. Hatchettine. 


Like soft wax in appearance and hardness, of a yellowish 
white to greenish yellow color. 

Composition. Related to paraffin. 

From the coal-measures of Glamorganshire in Wales. 


Ozocerite. Like wax or spermaceti in consistence; soluble in ether, 
The original was from Moldavia; along with another wax-like sub- 
stance, called Urpethite, it constitutes the ‘‘mineral wax of Urpeth 
Colliery.” Zetrisikite is like becswax, and is insoluble in cther; 
from Moidavia. Prosepnyte, of the mercury mine, Wake Co., Cal., 
is near ozoccrite. A large deposit of ozocerite, or a related material, 
is worked in Southern Utah. 


Elaterite.—Mineral Caoutchouc. Elastic Bitumen. 


In soft flexible masses, somewhat resembling caoutchouc 
or India-rubber. Color brownish black; sometimes orange- 
red by transmitted light. G.=0°9-1:25. Composition: 


348 DESCRIPTIONS OF MINERALS. 


Carbon 85°5, hydrogen 13:3 = 98°8. Burns readily with a 
yellow flame and bituminous odor. 
Obs. From a lead-mine in Derbyshire, England, and a — 
coal-mine at Montrelais. Has been found at Pe aaa 
Ct., in a bituminous limestone. 


“Fichtelite and Hartite are crystallized hydrocarbons, of the Cam- 
phene series; the former is mentioned from a log of Pinus Australis 
in Alabama. Branchite, Dinite, and Ixolyte are related to Hartite. 
Kinlite, Naphthalin, and Idréalite are native species of the Benzole 
series. Aragotiie, from California, is near Idrialite. 


II. OXYGENATED HYDROCARBONS. 
Amber. 


In irregular masses. Color yellow, sometimes brownish 
or whitish; lustre resinous. ‘Transparent to translucent. 
H.= 2-2°5. G.=1:18. Electric by friction. 

Amber is not a simple resin, but consists mainly (85 to 90 
per cent.) of a resin which resists all solvents, called Suc- 
cinite, and two other resins soluble in alcohol and ether, 
besides an oil, and 24 to 6 per cent. of Succinic acid. 

Obs. Occurs in the loose deposits of sand, etc., along 
coasts, especially those of Tertiary strata, in masses from a 
very small size to that of a man’s head. In the Royal 
Museum at Berlin there is a mass weighing 18 pounds. 
Most abundant on the Baltic coast, especially between 
Koénigsberg and Memel; also on the Adriatic; in Poland; 
on the Sicilian coast near Catania; in France near Paris, in 
clay; in China. It has been found in the U. States, at Gay 
Head, Martha’s Vineyard, and on Nantucket; Camden, and 
near Harrisonville (one mass 2061 in.), N. J.; and at 
Cape Sable, near the Magothy River, Md.; Pitt Co., and 
other eastern counties, N. C, 

It is supposed, with good reason, to be a vegetable resin 
altered somewhat chemically since burial, partly owing to 
acids of sulphur proceeding from decomposing pyrites or 
some other source. It often contains insects, and speci- 
mens of this kind are so highly prized as frequently to be 
imitated for the shops. Some of the insects appear evi- 
dently to have struggled after being entangled in the then 
viscous resin, and occasionally a leg or a wing is found some 
distance from the body, which had been detached in the 
effort to escape. 


ASPHALTUM AND MINERAL COALS. 349 


Amber is the elekiron of the Greeks; from its becoming 
electric so readily when rubbed, it gave the name electricity 
to science. It was also called szectnum, from the Greek 
succum, juice, because of its supposed vegetable origin. 

It admits of a good polish, and is used for ornamental 
purposes, though not very much esteemed, as it is wanting 
in hardness and brilliancy of lustre, and moreover is easily 
imitated. It is much valued in Turkey for mouth-pieces 
to pipes. 


Copaliie, or Mineral Copal, Gedanite, Walchowite, Neudorfite, Schrau- 
jite, Ambrite (the New Zealand resin), Huosmite, Scleretinite, Middle- 
tonite, Ajkite, Duxite, Krantzite, Siegburgite, are some of the names of 
other fossil resins ; Geocerite, and Geomyricite, of wax-like oxygenated 
species; Guyaquillite, Bathvillite, Ionite (from Ione valley, Cal.), of 
species not resinous in lustre ; Zasmanite and Dysodile, of linds con- 
taining several per cent. of sulphur. Celestéalite is a probable sul- 
pho-hydrocarbon from a meteorite. Zorbanite, or Boghead coal, is 
related in composition to amber. Wollongongite, from Harticy (not 
Wollongong), Australia, looks like cannel coal, but is near torbanite. 

Dopplerite. Elastic or partly jelly-like, and from a peat-bed. A 
similar material, from a peat-bed in Scranton, Pa., has been named 
Pihytocollite. 

Hofmannite. White efflorescence on lignite; in tabular crystals ; 
fuses easily to an oily fluid, and burns with a bright flame. Formula 
C2oH;.O. From near Siena, Italy. 


Ill. ASPHALTUM AND MINERAL COALS. 
Asphaltum. 


Amorphous and pitch-like. Burning with a bright flame 
and melting at 90° to 100° F. Soluble mostly or wholly in 
camphene. A mixture of hydrocarbons, part of which are 
oxygenated. 

Vbs. Asphaltum is met with abundantly on the shores of 
the Dead Sea, and in the neighborhood of the Caspian. A 
remarkable locality occurs on the island of Trinidad, where 
there is a lake of it about a mile and half in circumference. 
The bitumen is solid and cold near the shores; but grad- 
ually increases in temperature and softness toward the 
centre, where it is boiling. The ascent to the lake from 
the sea, a distance of three quarters of a mile, is covered 
with the hardened pitch, on which trees and vegetation 
flourish, and here and there, about Point La Braye, the 
masses of pitch look like black rocks among the foliage. 


350 DESCRIPTIONS OF MINERALS. 


Occurs also in South America about similar lakes in Peru, 
where it is used for pitching boats; in California on the 
coast of Santa Barbara. Large deposits occur in sandstone 
in Albania. Uintahite, from Uintah Mts., Utah, is similar. 


Albertite. 


Coal-like in hardness, but little soluble in camphene, and 
only imperfectly fusing when heated; but having the lustre 
of asphaltum, and softening a little in boiling water. H.= 
1-2. G.=1:°097. 

Fills fissures in the Subcarboniferous rocks near Hills- 
borough, Nova Scotia; supposed to have been derived from 
the hydrocarbon of the adjoining rock, and to have been 
oxidized at the time it was formed and filled the fissure. 


Grahamile. A related material from West Virginia, 20 miles south 
of Parkersburg (also from Huasteca, Mexico). H.=2; G.=1°145; 
soluble mostly in camphene, but melt sonly imperfectly; an analysis 
afforded Carbon 76°45, hydrogen 7°82, oxygen (with traces of nitrogen) 
18°46, ash 2°26 = 100. 


MINERAL COAL. 


Massive, uncrystalline. Color black or brown; opaque. 
Brittle or imperfectly sectilee H.=0°5-25. G@. =1°2- 
1°80. | 

Composition. Carbon, with some oxygen and hydrogen, 
more or less moisture, and traces also of nitrogen, besides 
some earthy material which constitutes the ash. The car- | 
bon, or part of it, is in chemical combination with the 
hydrogen and oxygen. Often contains some occluded 
marsh gas, whose escape, as pressure is removed, is one 
source of the gas of coal-mines. 

Coals differ in the amount of volatile ingredients given 
off when heated. These ingredients, besides moisture and 
some sulphur, are hydrocarbon oils and gas, derived from 
the same class of insoluble hydrocarbons that is the source 
of the oil of shales and other rocks. 


VARIETIES. 


1. Anthracite. (Glance coal, Stone coal). Lustre high, 
not resinous, sometimes submetallic. Color gray-black. 
H. = 2-2°5. G. = 1:57-1:67, if pure. Fracture often 


MINERAL COAL. 351 


conchoidal. Good anthracite contains 78 to 88 per cent. 
of fixed carbon (83 about an average) 2 to 3°5 of hydrogen, 
1°5 to 3°5 of oxygen with 4 to 12 p. c. of earthy impurities. 
The amount of volatile matter is but 3 to 7 p. c., and there is 
a trace of sulphur. Burns with a feeble blue flame. The 
kind yielding the most volatile ingredients is called free- 
burning anthracite. 

2. Bituminous coal. Color and powder black. Lustre 
usually somewhat resinous. H.=1°5-2. G.= 1°2-1°4, 
if pure; the Pittsburg, 1:23-1:28. Contains usually 75 to 
85 p. c. of carbon, 4 to 6 of hydrogen, 4 to 15 of oxygen, 
with mostly 2 to 9 p. c. of moisture. The volatile carbo- 
hydrogen ingredients 20 to 45 p. c., with 50 to over 60 in 
some kinds; sulphur in the best coals below 1 p. c., but 
often 2 to 2°5. Ash impurities 1°4—7°'5 p. c.; average 5 or 
6 p. c.; less than inanthracite, because anthracite was made 
out of bituminous coal by the expulsion of volatile ingredi- 
ents—a condensing process. Burns with a bright yellow 
flame. Yields little to, or colors slightly, if at all, a potash 
solution. , 

Caking Coal includes that part of bituminous coal which 
softens when heated and becomes viscid, so that adjoining 
pieces unite into a solid mass. It burns readily with a lively 
yellow flame, but requires frequent stirring to prevent its 
agglutinating, and so clogging the fire. Non-caking coal 
resembles the caking in appearance, but does not soften and 
cake. ‘I'he chemical difference between caking and non- 
caking coal is not understood. 

3. Cannel Coal. Very compact and even in texture, with 
littie lustre, and fracture large conchoidal. ‘Takes fire 
readily, and burns without melting with a yellow flame, and 
has hence been used for candles—whence the name. Vola- 
tile carbohydrogen compounds given out when heated 
amount to 40 to 50 p. c., and even 60; and hence valued 
for the manufacture of gas as well as for fuel; also yields 
much mineral oil. Cannel coal is often made into ink- 
stands and other similar articles. 

4. Brown Coal (often called Lignite). Color black to 
brownish black; of powder, brown. Contains 15 to 20 p. c. 
of oxygen, and often 8 to 10 p. c. of hygrometric moisture; 
fixed carbon mostly 52 to 65 p.c. Gives a brownish or 
brownish red color to a solution of potash. Usually non- 
caking. The kinds having more or less of the structure of 


352 DESCRIPTIONS OF MINERALS. 


wood are called Jignite; and in these kinds, the oxygen 
present may be 25 to over 30 p. c., and the moisture 15 to 20. 
p. c. Between the brown coals and bituminous coal there 
is a gradual passage in constitution and in color of powder. 

Jet resembles cannel coal, but is harder, of a deeper black 
and higher lustre. It receives a brilliant polish, and is set 
in jewelry. It is the Gagates of Dioscorides and Pliny, a 
name derived from the river Gagas, in Syria, near the 
mouth of which it was found, and the origin of the term 
jet now in use. Occurs in the Lower Odlite in Yorkshire. 

Native Coke resembles somewhat artificial coke, but is 
more compact, and some varieties of it afford a consider- 
able amount of bitumen. Occurs at the Edgehill mines 
near Richmond, Virginia, according to Genth, who attrib- 
utes its origin to the action of a trap eruption on bitumi- 
nous coal, 

The following are a few analyses of bituminous coals, etc., 
the moisture excluded: 


oa fee Hydr.| Oxyg.| Nitr. |Sulph.} Ash. 


























bon 
1) Caking Coal, Kentucky........... 74°45 | 4°93 | 13°08 1°03"); 0°91 5°00 
2) Caking Coal, Nelsonville, O....... 73°80 | 5:79-| 16°58 | 1°52) 50-415) eo 
3} Caking Coal, South Wales..... ..| 82°56 | 5°36 |} 8°22 | 1°65) 0°75 | 1:46 
4) Caking Coal, Northumberland....| 78°69 | 6°00 | 10°07 | 2°37 | 1°51} 1°36 
5' Non-caking, Kentucky............ 77°89 | 5:42 | 12°57 1°82 | 3°00} 2:00 
6| Non-caking, ‘t Black Coal,’’ Ind...| 82°70 | 4°77 | 9°89 | 1°62 | 0°45} 1°07 
%| Non-caking, Briar Hill, O......... 78°94 |. 5°92 | 11°50 |) 1°58 | 0°56} 4°45 
8| Non-caking, S. Staffordshire...... 76°40 | 4°62 | 17°43 ee 0:55 | 1°55 
9| Non-caking, Scotland............. “6°08 |. 5:31 | 18°33 °)2°2°099). 01-23 eee ue 
10} Cannel Coal, Breckenridge........ 68°13. | 6°49 | 5°83} 2°27} 2-48 | 12°30 
diCannel:Coal: Wigan... ..ukeccre ees 80°07 | 5°53 | 8°10" 22" ie nveieecere 
12} Cannel Coal, ‘‘ Torbanite”........ 64°02 8°90 | 5°66 0°55 | 0°50 | 20°82 
13] Albertite, Nova Scotia............ 86°04 | 8°96} 1°97 | 2°93 | trace} 0°10 
14} Brown Coal, Bovey............... 66°31 ; 5°63 | 22°86; 0°57 | 2°36; 2°27 
15| Brown Coal, Wittenberg....... aos | §64207-0) 4 5208? | 27455. vee esc 3°85 
16} Brown Coal, Carbon, Wy......... 73°55 |}. 4°17 1°17°20 | 2798 ee teed oe 
1?) Brown Coal, Carbon, Wy.........| 75°20.| 4°74 | 10°37 | 1°87} 1:11} 720 
18] Peat, light brown (imperfect)..... 50°86.| 5°80 | 42°57.| 20° tye ane 
19}Peat) dark Drown. os. doe ck ook. - 59°47 | 6°52 | 8r-ot 2°51 cate 
20|. Peat; Dlackens a% . fa recn's wits « obese 59°70 | 5°70 | 83°04 | 1°56 
eT TPE Ab DLAC Kon sis apatarecaps st stems sin aieeesrs 59°71 | 5°27 | 82°07 | 2°59 


It is now well established that mineral coal is mainly of 
vegetable origin, and that the accumulations out of which 
the coal-beds were made were very similar in character, 
though not in kinds of plants, to the peat-beds of the pres- 
ent day. Peat is vegetation which has undergone, in part, 
the change to coal; and in some cases it has become drown 
coal. The conditions of change are somewhat different from 


MINERAL COAL. 353 


those of the beds of good coal, since, in the case of the peat, 
the air has access, while in that of the coal the air was more 
or less excluded by overlying strata; and the more perfect 
the exclusion, other things equal, the better the coal. As 
the composition of mineral coal is closely related to that of 
mineral oils, the explanation of the origin of the latter, 
given on page 346, suffices to illustrate also the origin of 
the former. With a less complete exclusion of the air, 
oxygenated hydrocarbon compounds, like coal, would be a 
natural result. 


The ‘‘ Mineral Charcoal” of coal-beds differs little in composition 
from ordinary bituminous coal; there is less hydrogen and oxygen. 
Rowney obtained, for that of Glasgow and Fifeshire, Carbon 82°97, 
74°71; hydrogen 3°34, 2°74; oxygen 7:59, 7°67; ash 6:08, 14°86.. The 
nitrogen is included with the oxygen; it was 0°75 in the Glasgow char- 
coal. Exclusive of the ash, the composition is Carbon 88°36, 87:78; 
hydrogen 3°56, 3°21; Oxygen 7°28, 9°01. It has a fibrous look, and 
occurs covering the surfaces between layers of coal, and has been ob- 
served in coal of all ages. It is soft, and soils the fingers like char- 
coal; one variety of it is a dry powder. 

The ordinary ¢mpuwrities of coal, making up its ash, are silica, a 
little potash and soda, and sometimes alumina, with often oxide of 
iron, more or less pyrite or iron sulphide; besides, in the less pure 
kinds, more or less clay or shale. The amount of ash does not ordina- 
rily exceed 8 per cent., but it is sometimes 30 per cent.; and rarely it 
is less than 5 per cent. When not over 3 or 4 per cent. the whole may 
have come from the plants which contributed the most of the material 
of the coal, since the Lycopods have much alumina and lime sulphate 
in the ash, and the Equiseta much silica. 

There is present, in most coal, traces of iron sulphide (pyrite, 
marcasite, or pyrrhotite), sufficient to give sulphur fumes to the gases 
from the burning coal, and sometimes enough to make the coal value- 
less in metallurgical operations. Some thin layers are occasionally 
full of concretionary pyrite. The sulphur was derived from the plants 
or from animal life in the waters. Sulphur also occurs, in some coal 
beds, as a constituent of a resinous substance; and Wormley has shown 
that part of the sulphur in the Ohio coals is in some analogous state, 
there being not iron enough present to take the whole into combina- 
tion, 

The average amount of ash in eighty-eight coals from the southern 
half of Ohio, according to Wormley, is 4°718 per cent.; in sixty-six 
coals from the northern half, 5°120; in all, from both regions, 4°891; 
or, omitting ten, having more than ten per cent. of ash, the average is 
4°28. In eleven Ohio cannels, the average amount of ash was 12°827. 
The moisture in the Ohio coals, according to the analyses of Wormley, 
varies from 1°10 to 9°10 per cent. of the coal. In the Pittsburg coal 
(see analysis 8, above), the best of the bituminous, the amount of ash 
is 8 to4°5 p. c., of moisture 1°3-1°5 p. c., of sulphur less than 0°25 p. ¢. 


23 


354 DESCRIPTIONS OF MINERALS. 


The volatile ingredients of bituminous coal when purified are the 
gas used in illumination. It consists of marsh-gas and hydrogen (near 
80 p. c. of the two) with other heavier hydrocarbon vapors; some car- 
bon oxide, usually two per cent. or so of moisture, with traces of 
carbon dioxide and nitrogen. 

The value of coal as fuel, supposing its impurities excluded, depends 
on its density, the amount of moisture present, the amount of oxygen 

resent. 
: If 100 pounds of coal contain 20 per cent. of oxygen, this oxygen 
is 20 pounds of incombustible material; which serves, it is true, to 
produce combustion in the other ingredients, but in this only does 
work which atmospheric oxygen may do as well; and further, it pro- 
duces water by combination with hydrogen of the coal and so wastes 
part of the fuel. 

If the 100 pounds contain 10 per cent. of moisture, this is 10 pounds 
of incombustible material, which uses the heat derived from the com- 
bustion of the other ingredients in order to take the form of vapor , 
and escape. 

If much impurity—ash—is present, so that a slag is formed by the 
fusion, the heat used in producing and sustaining this fusion is 
much lost to the furnace. 

Moreover, the hydrocarbon gases that escape, producing flame, take 
up and dissipate much heat. 

On account of the conditions stated, anthracite is the best fuel for 
producing high heat. But for making steam in boilers flame is desir- 
able, and this requires that the coal should contain more hydrogen 
than exists in anthracite; the semi-anthracite ranks among the best in 
this respect, since it burns with flame and practically no smoke; hence 
it is sometimes called ‘‘ steam coal.” Most bituminous coals contain 
too much hydrogen, or yield, on heating, too much of volatile hydro- 
carbons, for the most economical production of steam, or for metal- 
lurgica] purposes, and hence the process adopted of subjecting the coal 
(the caking kind only is so used) to partial half-smothered combustion, 
and obtaining thus what is called coke. The coking drives off also 
from an eighth to a fourth of the sulphur present as pyrite or other- 
wise. The coke obtained is usually about 60 to 70 p. c. by weight of 
the coal used, but is of greater bulk. 

The calorific power of a coal—dependent on the number of pounds 
of water that may be evaporated in the complete combustion of a given 
amount of the coal—may be calculated from the amount of combusti- 
ble material, in the form of hydrogen and carbon, that is not lost, 
during the burning, from combination with the oxygen of the coal. 

Since 1 part by weight of hydrogen combines, in the combustion, 
with 8 of oxygen to form water, an anthracite consisting, ash ex- 
cluded, of 100 of carbon to 2°84 of hydrogen and 1°74 of oxygen, will 
have 2°62 of ‘‘ disposable hydrogen,” the 1°74 of oxygen carrying off 
1°74 + 8 or 0°22 p. c. of the hydrogen; and a bituminous coal, con- 
sisting of 100 carbon to 6:12 of hydrogen and 21°23 of oxygen, will 
have 8°47 of ‘‘ disposable hydrogen,” the 21°28 of oxygen carrying off 
2°65 of the hydrogen. If then the coal contained no impurities, and 
the combustion were complete (union with oxygen, converting all the 
carbon to carbon dioxide and all the hydrogen to water), and there were 


MINERAL COAL. 855 


no loss of heat by radiation or otherwise, the amount of heat it would 
generate, or its pyrogenic power, would be directly deduced from 
that of one pound of carbon 2731° C., and an equal weight of hydrogen 
2750° C. This gives only a theoretical result, since the loss of heat in 
practice is large, and from several sources, as already indicated. But 
the amount of ‘‘ disposable” hydrogen determines the value of the 
coal in gas-production. In Wigan Cannel there are only about 8 per 
cent. of oxygen, and hence 4'5 p. c. of ‘‘ disposable” hydrogen; while 
in Boghead Cannel, or Torbanite, the ‘‘ disposable” hydrogen is over 
8 per cent. 

Mineral coal occurs in extensive beds or layers, interstratified with 
different rock strata. The associate rocks are usually clay shales (or 
slaty beds) and sandstones; and the sandstones are occasionally coarse 
grit rocks or conglomerates. There are sometimes also beds of lime- 
stone alternating with the other deposits. 

Coal-beds vary in thickness from a fraction of an inch to 50 feet. 
The thickness of a bed may increase or diminish much in the course of 
a few miles, or the coal may become too shaly to work. 

The areas of the ‘‘ coal-measures” of the Carboniferous era, in the 
United States, are as follows: 

1. A small area in Rhode Island, continued northward into Massa- 
chusetts. 

2. A large area in Nova Scotia and New Brunswick, stretching east- 
ward and westward from the head of the Bay of Fundy. 

These two areas are now separated; but it is probable that they were 
once united along the region, now submerged, of the Bay of Fundy 
and Massachusetts Bay. 

3. The Alleghany Region, which commences at the north on the 
southern borders of New York, and stretches southwestward across 
Pennsylvania, West Virginia, and Tennessee to Alabama, and west- 
ward over part of Eastern Ohio, Kentucky, Tennessee, and a small 
portion of Mississippi. It may underlie the Tertiary and Cretaceous 
rocks of Mississippi and other Southern States, and so have a much 
greater extension in that direction than that of its present surface dis- 
tribution. 'To the north, the Cincinnati ‘‘ uplift,” an area of Silurian 
rocks extending from Lake Erie over Cincinnati to Tennessee, forms 
the western boundary. 

4, 'The Michigan coal area, an isolated area wholly confined within 
the lower peninsula of Michigan. 

5. The Eastern Interior area, covering nearly two thirds of Illinois, 
and parts of Indiana and Kentucky. 

6. The Western Interior area, covering a large part of Missouri, and 
extending north into Iowa, and southward, with interruptions, through 
Arkansas into Texas, and westward into Kansas and Nebraska. 

The Illinois and Missouri areas are connected now only through the 
underlying Subcarboniferous rocks of the age; but it is probable that 
formerly the coal-fields stretched across the channel of the Mississippi, 
and that the present separation is due to erosion along the valley. 

Rocks of the Carboniferous period extend over large portions of the 
reper Mountain area, but they are mostly limestones, and are barren 
of coal. . 


356 DESCRIPTIONS OF MINERALS. 


The extent of the coal-bearing area of these Carboniferous regions 
is approximately as follows: 


BOO ISSN AECH goes cw a'asi's 5 ony 2 ore 500 square miles. 
AICO PPCM tee Seas Ss eet us oes 59,000 square miles. 
WHCHISHN ATCO, oss hc Sorts ice ihtis i Ceoteos a 6,700 square miles. 
Illinois, Indiana, West Kentucky...... 47,000 square miles. 
Missouri, Iowa, Kansas, Arkansas, Texas 78,000 square miles, 
Nova Scotia and New Brunswick...... 18,000 square miles. 


The whole area in the United States is over 190,000 square miles, 
and in North America about 208,000. Of the 190,000 square miles 
perhaps 120,000 have workable beds of coal. 

Anthracite is the coal of Rhode Island, and of the areas in Central 
Pennsylvania, from the Pottsville or Schuylkill coal-field to the Lacka- 
wanna field, while the coal of Pittsburg, and of all the great coal- 
fields of the Interior basin, is détwmtnous, excepting a small area in 
_ Arkansas. Anthracite belongs especially to regions of upturned rocks, 
and bituminous coal to those where the beds are little disturbed. In 
the area between the anthracite region of Central Pennsylvania and 
the d¢/wminous of Western, and farther south, the coal is semé-bitwmin- 
ous, as in Broad Top, Pennsylvania, and the Cumberland coal-field in 
Western Maryland, the volatile matters yielded by it being 15 to 20 per 
cent. The more western parts of the anthracite coal-fields afford the 
free-burning anthracite, or semi-anthracite, as at Trevorton, Shamokin, 
and Birch Creek. 

The coal formation of the Carboniferous age in Europe has great 
thickness of rocks and coal in Great Britain, much less in Spain, 
France, and Germany, and a large surface, with little thickness of 
coal, in Russia. It exists, also, and includes workable coal-beds, in 
China, and also in India, Japan, and Australia; but, in part, the forma- 
tions in these latter regions are Permian and Triassic or Jurassic. No 
coal of the Carboniferous era has yet been found in South America, 
Africa, or Asiatic Russia. The proportion of coal-beds to area in dif- 
ferent parts of Europe has been stated as follows: in France, 1-100th of 
the surface; in Spain, 1-50th; in Belgium, 1-20th; in Great Britain, 
1-10th. But, while the coal area in Great Britain is about 12,000 
square miles, that of Spain is 4000, that of France about 2000, and 
that of Belgium 518. 

The amount of coal in exposed Carboniferous coal-fields of Great 
Britain, within 4000 feet of the surface, and regarded as workable, as 
deduced from investigations made by a Royal Commission in 1866-71, 
was reported in 1878 to be over $0,000,000,000 tons; more than a third 
of this in South Wales; a fifth in Yorkshire and Derbyshire; a ninth 
in Northumberland and Durham; nearly as much in Scotland; and as 
much also in Somersetshire, combined with that in Lancashire and 
Cheshire; and the rest, about 2-15ths of the whole, in other coal-areas. 
Besides this, it is estimated that there are over 56,000,000,000 tons of 
available coal underneath the Permian and other formations, making 
in all about 146,500,000,000 tons, which is ‘‘ 1070 times the amount of 
the present annual output of 125,000,000 tons.” 

_ Mineral coal of later age than the true Carboniferous era occurs in 


MINERAL COAL. 357 


various parts of the world. Besides Australia and India, Triassic or 
Jurassic coal, of the bituminous variety, occurs in thick workable 
beds in the vicinity of Richmond, Va., and has been worked in the 
Deep River and Dan River regions, N. C. In Scotland, at Brora in 
Sutherlandshire, there is a bed of Odlitic coal. Coal of the Cretaceous 
and Tertiary eras constitutes important beds in various parts of the 
Rocky Mountain region, in the vicinity of the Pacific Railroad and 
-elsewhere. Some of the prominent localities are: In Utah, at Evans- 
ton and Coalville (in the valley of Weber River), etc.; in Wyoming, at 
Carbon, 140 miles from Cheyenne; at Hallville, 142 miles farther 
west; at Black Butte station, on Bitter Creek; on Bear River, etc.; in 
the Uintah Basin, near Brush Creek, 6 miles from Green River; in 
Colorado, at Golden City, 15 miles west of Denver, on Ralston Creek, 
Coal Creek, 8. Boulder Creek and elsewhere; in N. Mexico, at the Old 
Placer Mines in the San Lazare Mountains, etc. ;and in British America, 
N. of Montana. The coal is of the bituminous or semibituminous 
kind, part of it true brown coal, but the rest more correctly referred 
to true bituminous coal. At the Old Plaeer Mines, New Mexico, the 
coal is in part anthracite, affording 88 to 91 per cent. of fixed carbon; 
the region is one of upturned and altered rocks, like the anthracite 
region of Pennsylvania. Other similar beds occur toward the Pacific 
coast, the most valuable of them in Washington Territory, near Seat- 
tle and at Bellingham Bay; also on Coos Bay, Oregon; on Vancouver 
and adjacent islands in British Columbia. Some anthracite, like that 
of N. Mexico in origin, occurs on the Queen Charlotte Islands. 


358 = SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


I. CATALOGUE OF AMERICAN LO- 
CALITIES OF MINERALS. 


Tue following catalogue of American localities of minerals is intro- 
duced as a Supplement to the Descriptions of Minerals. Its object is 
to aid the mineralogical tourist in selecting his routes and arranging 
the plan of his journeys. Only important localities, affording cabinet 
specimens, are in general included; and the names of those minerals 
which are obtainable in good specimens are distinguished by italics, 
When the name is not italicized, the mineral occurs only sparingly or 
of poor quality. When the specimens to be procured are remarkably 
good, an exclamation-mark (!) is added. 


MAINE. 


AuBany.—Beryl!/ green and black tourmaline, garnet, feldspar, rose 
quartz, rutile. 

ANDOVER.—See RUMFORD. 

AUBURN, w. part, near Minot line.—Lepidolite, amblygonite (hebro- 
nite), cassiterite, colorless, green, blue, and black tourmaline! apatite 
(Mt. Apatite). 

Batu.—Vesuvianite, garnet, magnetite, graphite. 

BrerueL.—Cinnamon garnet, calcite, sphene, beryl, pyroxene, horn- 
blende, epidote, graphite, talc, pyrite, arsenopyrite, magnetite. 

BineuamM.—WMassive pyrite, galenite, blende, andalusite. 

Buve Hitt Bay.—Arsenical iron, molybdenite! galenite, apatite! 
fluorite! black tourmaline (Long Cove), black oxide of manganese 
(Osgood’s farm), rhodonite, bog manganese, wolframite. 

Bowvorin.— Lose quartz. 

BowpornHamM.—Beryl, molybdenite. 

BRUNSWICK.—Green mica, garnet! black tourmaline / molybdenite, 
epidote, calcite, muscovite, feldspar, bery}. 

BucKFIELD.—Garnet (estates of Waterman and Lowe), muscovite / 
tourmaline / magnetite. 

CAMDAGE F'arM.—(Near the tide mills), molybdenite, wolframite. 

CAMDEN.—Wacle, galenite, epidote, black tourmaline, pyrite, talc, 
magnetite. 

Canton.—Chrysoberyl. 

CARMEL (Penobscot Co.).—Stibnite, pyrite, macle. 

Corinna.—Pyrite, arsenopyrite. 

DEER IsLE.—Serpentine, verd-antique, asbestus, diallage, magne- 
tite. 

DEXxTER.—Galenite, pyrite, blende, chalcopyrite, green talc. 

DIxFIELD.—Native copperas, graphite. 

. FarMINGTON.—(Norton’s Ledge), pyrite, graphite, garnet, stauro- 
ite. 

FRANELIN PLANTATION.—Beryl. 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 359 


FREEPORT.— Rose quartz, garnet, feldspar, scapolite, graphite, mus- 
covite, 

FRYEBURG.— Garnet, beryl. 

West GARDINER, along the Litchfield border. See LircHFIELD. 

GEORGETOWN.—(Parker’s Island), bery/ / black tourmaline. 

GorHAM.—Andalusite. 

GREENWOOD.— Graphite, black manganese, beryl / arsenopyrite, cas- 
siterite, mica, rose quartz, garnet, corundum, albite, zircon, molybden- 
ite, magnetite, copperas. 

HEBRON, 7 m. s. of Mt. Mica in Paris.—Lepidolite, amblygonite 
(hebronite), rubellite / indicolite, green tourmaline, damourite (as altered 
tourmaline), mca, beryl, apatite, albite, childrenite, cookeite, cassiterite, 
arsenopyrite, idecrase. 

Linn2Zvs.—Hematite, limonite, pyrite, bog-iron. 

LITCHFIELD.—Sodalite, cancrinite, elwolite, zircon, hydronephelite, 
spodumene, muscovite, pyrrhotite (from bowlders). 

LovELu.—Beryl. 

Lusec LEAD Minrs.—Galenite, chalcopyrite, blende. 

MACHIASPORT.—Jasper, epidote, laumontite. 

MADAWASKA SETTLEMENTS.— Vivianite. 

Minot.—Beryl, smoky quartz. 

Monmovutu.—<Actinolite, apatite, elgolite, zircon, staurolite, plumose 
mica, beryl, rutile. 

Mr. ApranAm.—Andalusite, staurolite. 

Norway.—Chrysoberyl ! molybdenite, beryl, rose quartz, orthoclase, 
albite, lepidolite, cinnamon garnet, triphylite (lithiophilite), cookcite, 
cassiterite, amblygonite. 

ORR’s IsLAND.—Steatete, garnet, andalusite. 

OxrorD— Garnet, beryl, apatite, wad, zircon, muscovite, orthoclase. 

Paris, on Mt. Mica.— Green / red ! black, and blue tourmaline ! mica! 
lenidolite / feldspar, albite, quartz crystals! rose quartz, cassiterite, am- 
blygonite, columbite, zircon, brookite, beryl, smoky quartz, spodu- 
mene, cookeile, leucopyrite, triphylite. 

PARSONSFIELD.— Vesuvianite! yellow garnet, pargasite, adularia, 
labradorite (cryst.), scapolite, galenite, blende, chalcopyrite. 

Prervu.—Crystallized pyrite, columbite, beryl, spodumene, triphylite 
(eryst.), chrysoberyl. 

PuiprspurG — Yellow garnet ! manganesian garnet, vesurianite, par- 
gasite, axinive, laumontite / chabazite, an ore of cerium? 

PoLAND.—Vesuvianite, smoky quartz, cinnamon garnet. 

PorRTLAND.— Prehnite, actinolite, garnet, epidote, amethyst, calcite. 

Pownau.—Black tourmaline, feldspar, scapolite, pyrite, actinolite, 
apatite, rose quartz. 

RaymMonvD.—Magnetite, scapolite, pyroxene, lepidolite, tremolite, horn- 
blende, epidote, orthoclase, yellow garnet, pyrite, vesuvianite. 

RockLAND.— Hematite, tremolite, guwartz, wad, tale. 

RumrorD.—On n. slope of Black Mtn., towrmaline (red), lepidolite, 
spodumene, cookeite, yellow garnet, vesuvianite, pyroxene, apatite, 
scapolite, cassiterite, amblygonite. 

SANFORD, York Co.— Vesuvianite! albite, calcite, molybdenite, epi- 
dote, black tourmaline, labradorite. 

SEARSMONT.—Andalusitz, tourmaline. 


360 SUPPLEMENT TO DESCRIPTIONS OF SPECIES, 


SovutH Brerwicx.—Chiastolite. 

SrTanpisH.—Columbite / tourmaline. 

SToNEHAM.—Columbite, chrysoberyl, herderite, topaz,.mica (curved), 
triplite. 

StowE.—Chrysobderyl, fibrolite. 

STREAKED Mountarwn.—Beryl / black tourmaline, mica, garnet. 

THOMASTON.— Calcite, tremolite, hornblende, sphene, arsenical iron 
(Owl’s Head), black manganese (Dodge’s Mountain), thomsonite, tale, 
blende, pyrite, galenite. 

TopsHaM.— Quartz, galenite, blende, tungstite? beryl, apatite, molyb- 
denite, columbite. 

Unton.—Magnetite, bog-ore. 

Wates.—Axinite in bowlder, alum, copperas. 

WATERVILLE.— Crystallized pyrite. 

WiInpDHAmM (near the bridge).—Staurolite, spodumene, garnet, beryl, 
amethyst, cyaniie, tourmaline. 

WinsLow.—Cassiterite. 
| WintrHrop.—Staurolite, pyrite, hornblende, garnet, copperas. 

Woopstock.— Graphite, hematite, prehnite, epidote, calcite. 

Yorx«.—Feryl, vivianite, oxide of manganese. 

The localities of lepidolite, green and red tourmalines, etc., in albite 
veins, occur in western Maine along a S. E. line from the Rangeley 
Lakes to a point between Brunswick and Portland, in Rumford, Paris, 
Norway, Hebron, and Auburn, about 40 m. in length. 


NEW HAMPSHIRE. 


AcwortTu.—Beryl! mica! tourmaline, orthoclase, albite, rose 
quartz, columbite/ cyanite, autunite. 

ALEXANDRIA.—Muscovite. 

AtsTEAD.—Mica!/ albite, black tourmaline, molybdenite, andalu- 
site, staurolite. 

AMHERST.— Vesuvianiie, yellow garnet, pargasite, amethyst, pyrox- 
ene, magnetite. 

BartTLeETT.—Magnetite, hematite, quartz crystals, danalite, limonite, 
smoky quartz. 

Batu.—Galenite, chalcopyrite, alum. 

Brprorp.—Tremolite, epidote, graphite, mica, tourmaline, alum, 
quartz, graphite. 

Brtitows Fartis.—Cyanite, staurolite, prehnite. 

Brenton.—Lpidote, beryl, magnetite. 

Brruin.—Chalcopyrite, pyrite, magnetite, hornblende. 

Bristou.— Graphite, galenite. 

Campton.— Beryl / 

CANAAN.—Gold in quartz veins and alluvium, garnet. 

CHARLESTOWN.—Staurolite, andalusite, prehnite, cyanite. 

ConcorpD.—Fibrolite. 

CornisH.—Rutile in quartz! (rare), staurolite, stibnite. 

Croypon.—Zolite/ chalcopyrite, pyrite, pyrrhotite, sphalerite, — 

ENFIELD.—Gold, galenite, staurolite, green quartz, ripidolite. 

FRANCESTON.—Soapstone, arsenopyrite, quartz crystals, 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 361 


Franconta.—Arsenopyrite, chalcopyrite. 

GARDNER Mtn.—Chalcopyrite, pyrite, galenite. 

GILMANTON.—Tremolite, epidote, muscovite, tourmaline, limonite, 
quartz crystals. 

GosHEN.— Graphite, black tourmaline. 

GrRAFTON.—Muscovite (quarried at Glass Hill, 2 m. 8. of Orange 
Summit), albiie/ blue, green, and yellow Jeryls/ (1m. 8. of O. Sum- 
mit), tourmaline, garnets, triphylite, apatite, fluorite, columbite, mo- 
lybdenite, rhodonite. 

GRANTHAM.— Gray staurolite [ 

Groton.—Arsenopyrite, deryl, muscovite crystals, orthoclase, colum- 
bite. 

HANOVER.— Garnet, black tourmaline, quartz, cyanite, epidote, 
anorthite, cyanite, zoisite. 

HAVERHILL.—Garnet ! arsenopyrite, native arsenic, galenite, 
blende, pyrite, chalcopyrite, magnetite, marcasite, steatite. 

HeEsron.—Beryl, andalusite, graphite. 
| HrnspaLe.—Rhodonite, molybdenite, indicolite, black tourmaline. 

JACKSON.—Drusy quartz, tin ore, arsenopyrite, native arsenic, jluo- 
rite, apatite, magnetite, molybdenite, wolframite, chalcopyrite. 

JAFFREY (Monadnock Mt.).—Cyanite, limonite. 

KEENE.— Graphite, soapstone, milky quartz, rose quartz. 

LANDAFF,—Molybdenite, magnetite, pyrrhotite. 

LrBpanon.—Limonite, arsenopyrite, galenite, magnetite, pyrite. 

Lispon.—Staurolite, garnets, magnetite, hornblende, epidote, zotsite, 
hematite, arsenopyrite, galenite, gold, ankerite. Franconia iron- 
mine, Hornblende, epidote, zoisite, hematite, magnetite, garnets, arseno- 
pyrite (danaite), molybdenite, prehnite, cyanite. 

LirrLeton.—Ankerite, gold, bornite, chalcopyrite, malachite, me- 
naccanite, chlorite. 

Lyman.—Gold, arsenopyrite, ankerite, dolomite, galenite, pyrite, 
pyrrhotite. 

LymE.—Cyanite (N. W. part), black tourmaline, rutile, pyrite, chal- 
copyrite (E. of E. village), stibnite, molybdenite, cassiterite, staurolite. 

Mapison.—Galenite, blende, chalcopyrite, limonite. 

Merrmack.—Rutile/ (in gneiss nodules in granite vein). 

MIDDLETOWN.—Autile, arsenopyrite. 

Miian.— Chalcopyrite, galenite, sphalerite. 

MILLSFIELD.—Beryl, garnets. 

Monapnock Mountarn.—Andalusite, hornblende, garnet, graph- 
- ite, tourmaline, orthoclase, fibrolite. 

New Lonpvon.—Beryl, molybdenite, muscovite. 

Newrport.— Molybdenite, staurolite. 

ORANGE.—Blue beryls/ Orange Summit, chrysoberyl, muscovite 
(W. side of mountain), albzte, tourmaline, apatite, galenite, limonite. 

ORFORD.—Brown tourmaline (obtained with difficulty), steatite, 
rutile, cyanite, menaccanite, garnet, graphite, molybdenite, pyrrhotite, 
melaconite, chalcopyrite, chalcocite, malachite, galenite, r7pidolite. 

PrerMoNT.—WMicaceous hematite, barite, mica, apatite. 

PriymovutH.—Columbite, beryl. 

RicHMonD.— Jolie, rutile, steatite, pyrite, anthophyllite, talc. 

Ryz.— Chiastolite (at Boar’s Head, in bowlders). 


362 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


SADDLEBACK Mt.—Black tourmaline, garnet, spinel. 

SHELBURNE.— Galenite, black blende, chalcopyrite, pyrite, pyrolusite, 

SPRINGFIELD.—Beryls (eight inches diameter), manganesian gar- 
nets! black tourmaline! in mica schist, albite, mica, rose quartz. 

SULLIVAN.— Tourmaline (black) in quartz, beryl. 

Surry.—Amethyst, galenite, tourmaline, cyanite. 

Surron.—Graphite, beryl. 

Unity (estate of James Neal).—Chalcopyrite, pyrite, chlorophyllite, 
green mica, actinolite, garnet, magnetite, tourmaline. 

WALPOLE.—Macle, staurolite, mica, graphite. 

W ARE.—Graphite. 

WarreEn.—-Chalcopyrite, blende, epidote, quartz, pyrite, tremolite, 
galenite, rutile, tale, molybdenite, cinnamon stone! pyroxene, horn- 
blende, beryl, cyanite, tourmaline (massive), pyrite. 

WATERVILLE.—Labradorite, chrysolite, amethyst. 

WESTMORELAND (south part).—Molybdenite ! apatite! blue feldspar, 
bog manganese (north village), quartz, amethyst, flworite, chalcopyrite, 
molybdite. 

Wurtz Mrs. (Notch near the ‘‘ Crawford House’’).—Green jfluwor- 
ate, quartz crystals, black tourmaline, andalusite, amethyst, amazon- 
stone. 

W HITEFIELD.— Molybdenite. 

WINCHESTER.—Pyrolusite, rhodonite, rhodochrosite, magnetite, 
pyrite, spodumene, tourmatine. 


VERMONT. 


AtTHeEns.—Sieatite, rhomb spar, actinolite, garnet. 

BALTIMORE.—Serpentine, pyrite [ 

BARNET.—Graphite. 

BELVIDERE.—Steatite, chlorite. 

BENNINGTON.—Pyrolusite, limonite. 

BERKSHIRE.—Lpidote, hematite, magnetite. 

BETHEL.—Actinolite / tale, chlorite, octahedral iron, rutile, brown 
spar in steatite. 

Branpon.—Pyrolusite, psilomelane, limonite, lignite, kaolinite, 
statuary marble; graphite. chalcopyrite. 

BRATTLEBOROUGH.—Black tourmaline in quartz, mica, zoisite, ru- 
tile, actinolite, scapolite, spodumene, roofing slate. 

BRIDGEWATER.— Tale, dolomite, magnetite, steatite, chlorite, gold, 
native copper, blende, galenite, blue spinel, chalcopyrite. 

Bristou.—Rutile, limonite, manganese ores, magnetite. 

BRookFIELD.—Arsenopyrite, pyrite. 

CaBboT.—Garnet, staurolite, hornblende, aldzte. 

CAVENDISH. —Garnet, serpentine, talc, steatite, tourmaline, asbestus, 
tremolite. 

CHESTER.—Asbestus, feldspar, chlorite, quartz. 

CHITTENDEN.—Psilomelane, pyrolusite, limonite, hematite and 
magnetite, galenite, iolite. 

CoLcHESTER.—Limonite, iron sand, jasper, alum. 

CorintH. —Chalcopyrite (has been mined), pyrrhotite, pyrite, rutile. 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 363 


CovEeNTRY.— Rhodonite. 

CRAFTSBURY.— Mica in concretions, calcite, rutile. 

DrrpBy.—Mica (adamsite). 

Ery.—Chalcopyrite, pyrite. 

Farr HAveN.—Roofing slate, pyrite. 

FARMINGTON.—Andalusite. 

FLETCHER.—Pyrite, magnetite, acicular tourmaline. 

Grarron.—The Grafton steatite quarry is in Athens; guariz, actin- 
olite. 

GUILFORD.—Scapolite, rutile. 

HARTFORD.— Calcite, pyrite! cyanite, quartz, tourmaline. 

IrRAsBuRGH.—Rhodonite, psilomelane. 

JAy.—Chromite, serpentine, amianthus, dolomite. 

LowrELL.—Picrosmine, amianthus, serpentine, cerolite,talc,chlorite. 

MARLBORO’.—Rhomb spar, steatite, garnet, magnetite, chlorite. 

MippLEsEx.—Rutile ! (exhausted). 

Monxton.—Pyrolusite, limonite, feldspar. 

Moretown.—Smoky quartz! steatite, tale, wad, rutile, serpentine. 

Mount Hoiiy.—Asbvestus, chlorite. 

New Fane.— Glassy and asbestiform actinolite, steatite, green quartz 
(called chrysoprase at the locality), chalcedony, dr usy quartz, garnet, 
chromic and titanic tron, rhomb spar, serpentine, rutile. 

Norwicu. — Actinolite, Seldspar, brown spar in talc, cyanite, zoisite, 
chalcopyrite, pyrite. 

PittsrorD.—Limonite, manganese ores, statuary marble | 

Puiymouru.—Siderite, magnetite, hematite, gold, galenite. 

Putnrey.—F luorite, limonite, rutile and zoisite in bowlders, staurolite. 

READING.— Glassy actinolite in talc. 

READSBORO’.— Glassy actinolite, steatite, hematite. 

RocuEstER.—Rutile, hematite cryst., magnetite in chlorite slate. 

RockrneHAM (Bellows Falls).—Cyanite, indicolite, feldspar, tour- 
maline, fluorite, calcite, prehnite, staurolite. 

Roxpury.—Dolomite, talc, serpentine, asbestus, quartz. 

RutTLanD.— Magnesite, white marble, hematite, serpentine. 

SHaRon.— Quartz crystals, cyanite. 

SuorEHAM.—Pyrite, black marble, calcite. 

STRAFFORD. —Magnetite and chaleopyn 1le (has been worked), native 
copper, hornblende, copperas. 

TurtrorD.—Blende, galenite, cyanite, chrysolite in basalt, pyrrho- 
tite. feldspar, roofing slate, steatite, garnet. 

TOWNSHEND. — Actinolite, black mica, talc, steatite, feldspar. 

Troy.—Magnetite, talc, serpentine, picrosmine, amianthus, steatite, 
one mile southeast of village of South Troy, on the farm of Mr. 
Pierce, east side of Missisco, chromite, zaratite. 

VERSHIRE.— Pyrite, chalcopyrite, tourmaline, arsenopyrite, quartz. 

W ARDSBORO’.—Zoisite, tourmaline, tremolite, hematite. 

WARREN.—Actinolite, magnetite, wad, serpentine. 

WATERBURY.—Arsenopyrite, chalcopyrite, rutile, quartz, serpen- 
tinc. 

WATERVILLE.— Sleatite, actinolite, tale. 

WEATHERSFIELD.—Steatite, hematite, pyrite, tremolte. 

WESTFIELD.—NSteatite, chromite, serpentine, 


364 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


WESTMINSTER. —Zoisite in bowlders. 
WinpuaM.—Glassy actinolite, steatite, garnet, serpentine. 
W oopstock.— Quartz crystals, garnet, zoisite. 


MASSACHUSETTS. 


Atuo..—Allanite, fibrolite (?), epidote! babingtonite ? 

AUBURN.— Masonite. 

BarreE.—Jutile! mica, pyrite, beryl, feldspar, garnet. 

GREAT BARRINGTON.—Tremolite. 

BEDFoRD.— Garnet. 

BELCHERTON.—Allanite. 

BERNARDSTON.—Magnetite at loc. of crinoidal limestone. 

BrEvERLY.—Columbite, green feldspar’, cassiterite. 

BLANFORD.—Serpentine, anthophyllite, actinolite! chromite, cyanite, 
rose quartz in bowlders. 

Bouton.—Scapolite / petalite, sphene, pyroxene, nuttalite, diopside. 
bolionite, apatite, magnesite, rhomb spar, allanite, yttrocerite/ spinel. 

BoxBorovueH.—Scapolite, spinel, garnet, augite, actinolite, apatite. 

BRIMFIELD (road leading to Warren).—Jolite, andalusite, adularia, 
molybdenite, mica, garnet. 

CARLISLE.—7/ourmaline, garnet ! scapolite, actinolite. 

CHARLESTOWN.—Prehnite, laumontite, stilbite, chabazite, quartz 
crystals, melanolite. 

CHELMSFORD.—Scapolite (chelmsfordite), chondrodite, blue spinel, 
amianthus / rose quartz. 

CuHESTER.—Hornblende, scapolite, zoisite, spodumene, indicolite, 
apatite, magnetite, chromite, stilbite, heulandite, analcite, and cha- 
bazite. At the Emery Mine, Chester Factories.—Corundum, marga- 
vite, diaspore, epidote, corundophilite, chloritoid, tourmaline, menac- 
canitte, rutile, biotite, cyanite, amesite. 

CHESTERFIELD,— Blue, green, and red tourmaline, cleavelandite 
(albite), lepidolite, smoky quartz, microlite, spodumene, cyanite, apatite, 
beryl, garnet, quartz crystals, staurolite, cassiterite, columbite, zoisite, 
uranite, brookite (eumanite), scheelite, anthophyllite, bornite. 

Conway.—Pyrolusite, fluorite, zoisite, rutile / native alum, gale- 
nite. 

CummMineton.—hodonite / cammingtonite (hornblende), marcasite, 
garnet, 

DEERFIELD.—Chabazite, heulandite, stilbite, datolite, prehnite, 
natrolite, analcite, calcite, fluorite, diabantite, saponite, amethyst, 
carnelian, chalcedony, agate, pyrite, malachite. 

FircHpure (Pearl Hill).— Beryl, stawrolite / garnets, molybdenite. 

FoxporovueH.—Pyrite, anthracite. 

FRANKLIN.—Amethyst. 

GLOUCESTER. —Danalite, 

GosHEN.— Mica, albite, spodumene! blue and green tourmaline, 
beryl, zoisite, smoky quartz, columbite, tin ore, galenite, beryl (goshen- 
ite), cymatolite (faixture of albite and muscovite). 

GREENFIELD (in sandstone quarry, + m. E. of village).—Allophane. 

HAtFIELD.—Barite, galenite, blende, chalcopyrite, quartz crystals. 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 365 


Hawtry.—Micaceous iron, massive pyrite, magnetite, zoisite. 

Heatu.—Pyrite, zoisite. 

HrnsDALE.—Limonite, apatite, zoisite. 

HuErparpston.— Massive pyrite. 

HuNTINGTON (name changed from Norwich).—Apatite/ black tour- 
maline, beryl, spodumene ! triphylite (altered), blende, quartz crystals, 
cassiterite. 

LANCASTER.— Cyanite, chiastolite/ apatite, staurolite, pinite, anda- 
lusite. 

Lrr.—Tremolite, sphene, chondrodite in South Lee. 

LEVERETT.—Barite, galenite, blende, chalcopyrite. 

LEYDEN.—Zoisite, rutile. 

MARBLEHEAD.—In zircon syenyte, sodalite, elzolite. 

MARrtTHA’s VINEYARD.—Limonite, amber, radiated pyrite. 

Mernvon.—WMica !/ chlorite. 

MIDDLEFIELD.—Glassy actinolite, rhomb spar, steatite, serpentine, 
feldspar, drusy quartz, apatite, zoisite, nacrite, chalcedony, talc / 
deweylite. 

Mitpory.— Vermiculite. 

New BRrRAINTtTREE.— Black tourmaline. 

Newsury.—<Serpentine, chrysotile, epidote, massive garnet, siderite. 

NEWBURYPORT.—Serpentine, nemalite, uranite.—Argentiferous ga- 
lenite, tetrahedrite, chalcopyrite, pyrargyrite, etc. 

Nortur1eLp.— Columbite, fibrolite, cyanite.. 

Norwicu.—See HUNTINGTON. 

PauMER (Three Rivers).— /eldspav, prehnite, calcite. 

PELHAM.—Asbestus, serpentine, quartz crystals, beryl, molybdenite, 
green hornstone, epidote, amethyst, corundum, vermiculite (pelhamite). 

PLAINFIELD.— Cummingtonite, prolusite, rhodonite. 

RicHMonpD.—Limonite, gibbsite! allophane. 

Rockport (near the extremity of C. Ann).—Danalite, eryophyllite, 
annite, cyrtolite (altered zircon), amazonstone, fergusonite, lepidome- 
lane, green and white orthoclase. 

Rowe. —KEpidote, talc ; at Davis mine, p yrite, chalcopyrite, gah- 
nite, zoisite. 

Sourn Royatston.— Beryl / (now obtained with difficulty), mica / 
Jeldspar / allanite. Four miles beyond old loc., on farm of Solomon 
Heywood, mica! beryl! feldspar! menaccanite. 

RussEL.— Garnet / mica, serpentine, beryl, galenite, chalcopyrite. 

SALEM.—Cancrinite, sodalite, eleolite, zircon. 

SHEFFIELD.— A sbestus, pyrite, native alum, pyrolusite, rutile. 

SHELBURNE.— Rutile. 

SHUTESBURY (east of Locke’s Pond).—Molybdenite. 

SouTHAMPTON.—Galenite, cerussite, anglesite, wulfenite, fluorite, 
barite, pyrite, chalcopyrite, plende, phosgenite, pyromorphite, stolzite, 
chrysocolla. 

STERLING.—Spodumene, chiastolite, siderite, arsenopyrite, dlende, 
galenite, chalcopyrite, pyrite, sterlingite (damourite). 

STONEHAM.—NVephrite. 

STURBRIDGE.— Graphite, garnet, apatite, bog-ore. 

Swampscot.—Orthite, feldspar. 

TAUNTON (one mile south). —Paracolumbite (titanic iron). 


366 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


TURNER'S Fauus (Conn. River).—Chalcopyrite, prehnite, chlorite, 
siderite, malachite. 

TyRINGHAM andon borders of OT18s.—Pyrozene, scapolite, chondro- 
dite, sphene, hornblende, spherostilbite. 

Warwick.—WMassive garnet, radiated black tourmaline, magnetite, 
beryl, epidote. 

W ASHINGTON.—Graphite. 

WESTFIELD.—Schiller spar (diallage), serpentine, steatite, cyanite, 
" scapolite, actinolite. 

WESTFORD.—Andalusite / 

West HamptTon.—Galenite, argentine, pseudomorphous quart. 

WEsT STOCKBRIDGE.— Limoniie, fibrous pyrolusite, s¢derite. 

WILLIAMSBURG.—Zoisite, pseudomorphous quartz, apatite, rose and 
smoky quartz, galenite, pyrolusite, chalcopyrite. 

WINpDsoR. —Zoisite, actinolite, rutile / 

WorceEsTER.—Arsenopyrite, idocrase, pyroxene, garnet, amianthus, 
bucholzite, siderite, galenite. 

W oRTHINGTON. — Cyanite, 

ZOAR.—Bitter spar, tale. 


RHODE ISLAND. 


BristTou.— Amethyst. 

Cranston.—Actinolite in talc, graphite, cyanite, mica, melanterite. . 

CUMBERLAND.— Manganese, epidote, actinolite, garnet, titaniferous 
iron, magnetite, hematite, chalcopyrite, bornite, malachite, azurite, 
calcite, apatite, feldspar, zoisite, mica, quartz crystals, ilvaite. 

DiamMonpD HiLu.—Quartz crystals, hematite. 

FostER.—Cyanite, hematite. 

GLOUCESTER.— Magnetite in chlorite slate, feldspar. 

JOHNSTON.—Talc, brown spar, calcite, garnet, epidote, pyrite, he- 
matite, magnetite, chalcopyrite, malachite, azurite. 

Natic.—See WARWICK. 

NEWPORT.—Serpentine, quartz crystals. 

PortsmMouTH.— Anthracite, graphite, asbestus, pyrite, chalcopyrite. 

SMITHFIELD.— Dolomite, calcite, bitter spar, siderite, nacrite, serpen- 
tine (bowenite), tremolite, asbestus, quartz, magnetite in chlorite 
schist, tale / octahedrite, feldspar, beryl. 

VALLEY F'stis.—Graphite, pyrite, hematite. 

Warwick (Natic village).—dasonite, garnet, graphite, bog-ore. 

WESTERLY.—Menaccanite. 

W oonsocKkET.—Cyanite. 


CONNECTICUT. 


BER.LIN.—Barite, datolite, blende, quartz crystals. 

Bouton. —Staurolite, chalcopyrite. 

BRANCHVILLE.—Pyroxene, garnet. Albite, microcline. amblygonite, 
spodumene! cymatolite, margarodite (curved), eosphorite, triploidite, 
reddingite, dickinsonite, lithiophilite, rhodochrosite, fairfieldite, apa: 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 367 


tite, microlite, columbite / garnet, pyrite, tourmaline, staurolite, wrani- 
nite, torbernite, autunite, vivianite, eucryptite, chabazite, stilbite, 
heulandite. 

BristoLt.—Chalcocite, chalcopyrite, barite, bornite, allophane, pyro- 
morphite, calcite, malachite, galenite, quartz. 

BROoKFIELD.—Galenite, calamine, blende, spodumene, pyrrhctite, 
chalcopyrite. 

CANAAN.—Tremolite and white pyrozene! in dolomite, canaanite 
(massive pyroxene). 

CHATHAM.—Arsenopyrite, smaltite, cloanthite (chathamite), scoro- 
dite, niccolite, beryl, erythrite. 

CHESHIRE.— Barite / chalcocite, bornite, malachite, kaolin, natro- 
lite, prehnite, chabazite, datolite. 

CHESTER.—Sillimanite/ zircon, epidote. 

CORNWALL.— Graphite, pyroxene, actinolite, sphene, scapolite. 

Dansury.—Danburite with oligoclase (formerly), brown tourmaline, 
orthoclase, pyroxene, parathorite. 

FARMINGTON.—Prehnite, chabazite, agate, native copper, diabantite. 

Happam.—Chrysoberyl / (not accessible), beryl, epidote, tourmaline, 
orthoclase, garnet, tolite! chlorophyllite! oligoclase, automolite, mag- 
netite, adularia, apatite, columbite/ (hermannolite), zircon (calypto- 
lite), mzca, pyrite, marcasite, molybdenite, allanite, bismuth ochre, 
bismutite. 

HapiLyME.—Chabazite and stilbite in gneiss. 

HARrtTrorD.— Datolite (Rocky Hill quarry). 

LITCHFIELD.— Cyanite with corundum, apatite, and andalusite, me- 
naccanite (washingtonite), chalcopyrite, diaspore, niccoliferous pyrrho- 
tite, margarodite, staurolite. 

LymME.—Garnet, sunstone, microcline. 

MeErIDEN.— Daiolite (greenish), diabantite. 

MIDDLEFIELD Fauus.—Datolite, chlorite, etc., in amygdaloid. 

MIDDLETOWN.—Mica, albite, feldspar, columbite! prehnite, garnet, 
beryl, topaz, uranite, apatite, pitchblende, lepidolite with green and 
red tourmaline ; at lead-mine formerly galenite, chalcopyrite, blende, 
quartz, calcite, fluorite, pyrite sometimes capillary. 

Miirorp.—Sahlite, pyroxene, asbestus, verd-antique marble, 

New HAven.—Serpentine, sahlite, stilbite, lanmontite. 

NEwtown.—Cyanite, diaspore, rutile, damourite. 

Norwicn.—Sillimanite, monazite / tolite, corundum, feldspar. 

PorTLAND.—Orthoclase, albite, muscovite, biotite, beryl, tourmaline, 
columbite, apatite ; at Pelton’s feldspar quarry, movazite. 

PLyMouTH.—Galenite, hewlandite, fluorite, chloryphyllite! garnet. 

Roarine Brook (Cheshire).— Datolite/ calcite, prehnite, saponite. 

Roxsury.—Siderite, blende, pyrite! galenite, quartz, chalcopyrite, 
arsenopyrite, limonite. 

SaLispury.—Limonite, pyrolusite, manganite, triplite, turgite, sco- 
villite, staurolite. 

SreyMouR.—Arsenopyrite, pyrite. 

SruspuRy.—Chalcocite, green malachite. 

SourHBury.—Rose quartz, laumontite, prehnite, calcite, barite. 

Soursineron.—Barite, datolite, asteriated quartz crystals, diaban- 
tite. 


368 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


STAFFORD.— Massive pyrite, alum, copperas. 

TARIFFVILLE.—Daitolite / 

TRUMBULL and Monror.— Ohlorophane, topaz (vein not open), beryl, 
diaspore, pyrrhotite, pyrite, schcelite, wolframite (pseudomorph of 
scheelite), native bismuth, tungstic acid, siderite, arsenopyrite, argen- 
tiferous galenite, blende, scapolite, tourmaline, garnet, albite, augite, 
graphic tellurium (?), margarodite. 

WaAsHINGTON.—TZ?ripolite, menaccanite! (washingtonite of Shep- 
ard), rhodochrosite, natrolite, andalusite (New Preston), cyanite. 

WATERTOWN, near the Naugatuck.— White sahlite, monazite. 

West Farms.—Asbestus. 

WILLIMANTIC.— Topaz, monazite, ripidolite. 


NEW YORK. 


ALBANY CO.—BEtTHLEHEM.—Calcite, stalactite, calcareous sin- 
ter, snowy gypsum. 

CoEBYMAN’s LANDING.—Gypsum, epsom salt, quartz crystals at 
Crystal Hill, 8m. 8. of Albany. 

WATERVIIET.— Quartz crystals, yellow drusy quartz. 

CAYUGA CO.—AuBuRN.—Celestite, calcite, fluor spar, ep: 
somite. 

SprineportT.—At Thompson’s plaster-beds, sulphur, selenite, 

Union Sprines.—Selenite, gypsum. 
= CLINTON CO.—Arnotp Iron Mine.—WMagnetite, epidote, mo- 
lybdenite. 
— Frncw OrE Bep.—Calcite, green and purple fluor. 

PLATTsBURG.—Nug¢get of platinum in drift. 

* COLUMBIA CO.—ANncrAmM.—Lead-mine, galenite, blende, wul- 
fenite, chalcopyrite. 

CANAAN.—Chalcocite, chalcopyrite, argentiferous galenite. 

CopakE.—Limonite (large ore-beds), 

Hupson.—Selenite. 

New Lresanon.—Nitrogen springs, epsom salt, brown spar, wad, 
siderite. 

DUTCHESS CO.—AmentrA.—Dolomite, liémonite, turgite, siderite. 

DovER.—Dolomite, tremolite, garnet, (Foss ore-bed) lmonite, 
staurolite. 

FisHkILu.—Dolomite; near Peckville, talc, asbestus, graphite, 
hornblende, augite, actinolite, hydrous anthophyllite, lémonite. 

Nort East.—Chalcocite, chalcopyrite, galenite, blende. 

Unton VaLE.—At the Clove mine, gibbsite, limonite. 

ESSEX CO.—ALEXxANDRIA.—Kirby’s graphite mine, graphite, 
pyroxene, scapolite, sphene. 

Crown Pornt.—Apatite (eupyrchrcite of Hmmons), brown tourma- 
line/ in the apatite, chlorite, quartz crystals, calcite, pyrite; S. of 
J. C. Hammond’s house, garnet, scapolite, chalcopyrite, aventurine 
feldspar, zircon, magnetite (Peru), epidote, mica. 

KrENE.—Scapolite. 

Lrewis.— Tabular spar, colophonite, garnet, labradorite, hornblende, 
actinolite; 10 m. 8. of Keeseville, arsenopyrite. 
~~ Lone Ponp.—Apatite, garnet, pyroxene, idocrase, coccolite! scapo- 
lite, magnetite, blue calcite. 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 369 | 


~— MoeIntyre.—Labradorite, garnet, magnetite. 

Mortrau, at Sandford Ore Bed. —Magnetite, apatite, allanite! lan- 
thanite, actinolite, and feldspar; at Fisher Ore Bed, magnetite, feld- 
spar, quartz; at Hall Ore Bed, or ‘‘ New Ore bed,” magnetite, Zi7'cons ; 
on Mill brook, calcite, pyroxene, hornblende, albite; in the town of 
Moriah, magnetite, black mica ; Barton Hill Ore-bed, albite. 

NEWComB. —Labradorite, feldspar, m magnetite, hypersthene. 

— Porr Henry.—Brown tour: maline, black tourmaline enclosing or- 
thoclase, mica, rose quartz, serpentine, green and black pyroxene, horn- 
blende, pay ste pyrite, graphite, wollastonite, pyrrhotite, adularia ; 
phlogopite | at Cheever Ore Bed, with magnetite and serpentine; in 
Champlain iron region, uranothorite. 

— RoaeEr’s Rock. — Graphite, wollastonite, garnet, feldspar, adularia, 
pyroxene, sphene, coccolite. 

—. Scrroon.— Calcite, pyroxene, chondrodite. 

TICONDEROGA.—Graphite! pyroxene, sahlite, sphene, black tour- 
maline, cacoxenite? (Mt. Defiance). 

Wesrrort.—Labradorite, prehnite, magnetite. 

— WILLSBORO’ .— Wollastonite, colophonite, garnet, green coccolite, 

hornblende. 

— GREENE £O.—Dramonp Hitu.—Quartz crystals. 
HERKIMER CO.—FatrFie_p.— Quartz crystals, fetid barite. 
LirtLE Faiis.— Quartz crystals! barite, calcite, smoky quartz; 

1m. 8. of Little Falls, calcite, brown spar, feldspar. 

MIDDLEVILLE.— Quartz crystals / calcite, brown and pearl spar. 

NEwrport.— Quartz crystals, 

SALISBURY.— Quartz crystals / blende, galenite, pyrite, chalcopy- 
rite. 

_— Srarx.—Fibrous celestite, gypsum. 

JEFFERSON CO.—Apams.—Fluor, calc tufa, barite. 

ALEXANDRIA.—On §. E. bank of Muscolonge Lake, fluorite (ex- 
hausted), phlogopite, chalcopyrite, apatite; on High Island, in the St. 
Lawrence River, feldspar, tourmaline, hornblende, orthoclase, celes- 
tite. 

ANTWERP. —Sterling iron-mine, hematite, chalcodite, siderite, mai- 
lerite, red hematite, crystallized quartz, yellow aragonite, niccoliferous 
pyrite, quartz crystals, pyrite; at Oxbow, calcite’ porous coralloidal 
heavy spar; near Vrooman’s lake, calcite / vesuvianite, phlogopite / 
pyroxene, sphene, fluorite, pyrite, chalcopyrite ; also feldspar, bog-tron 
ore, scapolite (farm of Eggleson), serpentine, tourmaline (yellow, 
rare 

Bpaiatiol 6. —Celestite, calcite (4m. from Watertown). 
-Naroura Bripeu.—Giesechite! steatite pseudomorphous after py- 
roxene, apatite. 

= New Connecticut.—Sphene, brown phlogopite. 
~Omar.—Beryl, feldspar, hematite. 

PHILADELPHIA.—Garnets on Indian River, in the village. 
~Pinttar Pornt.—AMassive barile (exhausted). 

THERESA.—Fluorite, calcite, hematite, hornblende, quartz crystal, 
serpentine (associated with hematite), celestite, strontianite. 

WATERTOWN.—7'remolite, agaric mineral, calc tufa, celestite. 

_ Wiina.—One mile N. of Natural Bridge, calcite. 


24 


370 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


LEWIS CO.—Drana (localities mostly near junction of crystal- 
line and sedimentary rocks, and 2 m. from Natural Bridge).—Scapo- 
lite! wollastonite, green coccolite, feldspar, tremolite, pyroxene! 
sphene! mica, quartz crystals, pyrite, pyrrhotite, blue calcite, serpen- 
tine, rensselaerite, zircon, graphite, chlorite, hematite, bog-ore, 
apatite. 

GrREIG.—Magnetite, pyrite. 

Lowvi.LEe.— Calcite, fluorite, pyrite, galenite, blende, calc tufa. 

MantTinspurGH.— Wad, galenite, etc. (formerly), calcite. 

MONROE CO.—RocuHEster.—Pearl spar, calcite, snowy gyp- 
sum, fluor, celestite, galenite, blende, barite, hornstone. 

MONTGOMERY CO.—Paatine.— Quartz crystals, drusy quartz, 
antiracite, hornstone, agate, garnet. 

Root.—Drusy quartz, blende, barite, stalactite, galenite, pyrite. 

NEW YORK CO.—KInNGSBRIDGE.—Tvremolite, pyroxene, mica, 
tourmaline, pyrite. 

New Yor«.—Serpeniine, amianithus, actinolite, pyroxene, hydrous 
anthophyllite, garnet, staurolite, molybdenite, graphite, chlorite, 
beryl, jasper, necronzte, feldspar. In the excavations for the 4th 
Avenue tunnel, 1875, harmotome, stilbite, chabazite, heulandite, etc. 

NIAGARA CO.—LrEwiston.—psomite. 

Locxport.—Celestite, calcite, selenite, anhydrite, fluorite, dolomite, 
sphalerite. 

NIAGARA FAuus.—Calcite, fluorite, blende, dolomite. 

—« ONEIDA CO.—BoonviILLE.— Calcite, wollastonite, coccolite. 

Cuinton.—Blende, lenticular hematite in the Clinton group, stron- 
tianite, celestite, the former covering the latter. 

ONONDAGA. CO.—CaAmILuus.—Selenite and fibrous gypsum. 

SyRAcusE.—Serpentine, celesiite, selenite, barite. 

ORANGE CO.—CorRNWALL.—Zircon, chondrodite, hornblende, 
spinel, feldspar, epidote, hadsonite, menaccanite, serpentine, coccolite. 
~~ DEER PAarKx.—Cryst. pyrite, galenite. 

Monroer.—Jlica! sphene! garnet, colophonite, epidote, chondrodite, 
allanite, bucholzite, brown spar, spznel, hornblende, tale, menaccanite, 
pyrrhotite, pyrite, chromite, graphite, rastolyte, moronolite; Wilks 
and O’Neill Mine, aragonite, magnetite, dimagnetite (pseud.?), jen- 
kinsite, asbestus, serpentine, mica, hortonolite ; Two Ponpns, pyroxene / 
chondrodite, hornblende, scapolite! zircon, sphene, apatite; GREEN- 
woop Furnace, chondrodite, pyroxenc! mica, hornblende, spinel, 
scapolite, biotite! menaccanite. 

Forest oF DEan.—Pyrovene, spinel, zircon, scapolite, hornblende. 

Town ofr WARWICK, WARWICK VILLAGE.—Spinel/ zircon, ser- 
pentine! brown spar, pyroxene! hornblende! pseudomorphous steatite, 
feldspar! (Rock Hill), menaccanite, clintonite, tourmaline (R. H.), 
rutile, sphene, molybdenite, arsenopyrite, marcasite, pyrite, yellow 
iron sinter, quartz, jasper, mica, coccolite. 

Amity.—Spinel/ garnet, scapolite, hornblende, vesuvianite, epidote / 
clintonite! magnetite, tourmaline, warwickite, apatite, chondrodite, 
tale! pyrowene! rutile, menaccanite, zircon, corundum, feldspar, 
sphene, calcite, serpentine, schiller spar (?), silvery mica. 

- DENVILLE.—Apatite, chondrodite! hair-brown hornblende! tremo- 
lite, spinel, tourmaline, warwickite, pyroxene, sphene, mica, feldspar, 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 371 


arsenopyrite, orpiment, vwtile, menaccanite, scorodite, chalcopyrite, 

leucopyrite (or léllingite), allanite. 

; West Pornt.—/eldspar, mica, scapolite, sphene, hornblende, al- 

anite. 

PUTNAM CO.—BrewsteRr, Tilly Foster Iron Mine.—Chondro- 
dite! magnetite, dolomite, serpentine pseudomorphs, brucite, enstatite, 
vipidolite, biotite, actinolite, pyrrhotite, fluorite, albite, epidote, sphene, 
apophylite. 

ANTHONY’s Noss, at top, pyrite, pyrrhotite, pyroxene, hornblende, 
magnetite. 

CARMEL (Brown’s quarry).—Anthophyllite, arsenopyrite, epidote. 

CoLp Sprine.—Sphene, epidote. 

PatTrERson.— White pyroxene! calcite, asbestus, tremolite, dolomite, 
massive pyrite. 
~ PHILLIPstown.—Tremolite, amianthus, serpentine, sphene, diopside, 
green coccolite, hornblende, scapolite, stilbite, mica, laumontite, gur- 
hofite, calcite, magnetite, chromite. 

_.Pmiuuirs Ore Bed.—Hyalite, actinolite, massive pyrite. 
RICHMOND CO.—RossvitLeE.—Lignite, cryst. pyrite. 
QUARANTINE.—Asbestus, amianthus, aragonite, dolomite, gurhofite, 

brucite, serpentine, talc, magnesite. 

ROCKLAND CO.—CALpDWELu.— Calcite, 

~ LADENTOWN.—Zircon, malachite, cuprite. 

PrerMontT.—Datolite, stilbite, apophyllite, pectolite, prehnite, 
thomsonite, calcite, chabazite. 

ST. LAWRENCE CO.—Canton.—WMassive pyrite, calcite, brown 
tourmaline, sphene, serpentine, talc, rensselaerite, pyroxene, hematite, 
chalcopyrite. 

Dr Kaxts.—Hornblende, barite, fluorite, tremolite, tourmaline, white 
tourmaline, blende, graphite, pyroxene, diopside quartz (spongy), 
serpentine. 

Epwarps.—Brown and silvery mica! scapolite, apatite, guartz crys- 
tals. actinolite, tremolite / hematite, serpentine, magnetite. 

Fine.— Black mica, hornblende. 

Fow.er.—Barite, quartz crystals / hematite, blende. galenite, tremo- 
lite, chalcedony, bog-ore, satin spar (assoc. with serpentine), pyrite, 
chalcopyrite, actinolite, rensselaerite (near Somerville). 

GouUVERNEUR.— Calcite! serpentine! hornblende! scapolite! ortho- 
clase, tourmaline! idocrase (1 m. 8. of G.), pyroxene, malacolite, 
apatite, rensselaerite, serpentine, sphene, fluorite, barite (farm of Judge 
Dodge), black mica, phlogopite, tremolite / asbestus, hematite, graph- 
ite, vesuvianite (near Somerville in serpentine), spinel, houghite, 
scapolite, phlogopite, dolomite; 2 m. W. of Somerville, chondrodite, 
spinel; 2m. N. of Somerville, apatite, pyrite, brown tourmaline ! / 

HammonvD.—Apatite/ zircon! (farm of Mr. Hardy), orthoclase 
(loxocase), pargasite, barite, pyrite, purple fluorite, tremolite, phlogo- 
pite. 

HerRMon.— Quartz crystals, hematite, siderite, pargasite, pyroxene, 
serpentine, tourmaline, bog-iron ore. 

Macoms.—Blende, mica, galenite (on land of James Averill), 
sphene, peristerite. 


ote SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


MINERAL Pornt, Morristown.—Fluorite, blende, galenite, phlogo- 
pite (Pope’s Mills), barite. 

OGDENSBURGH.—Labradorite. 

PIERREPONT.—Tourmaline, sphene, scapolite, hornblende, pyr- 
oxene. 

PrircarRN.—Satin spar, associated with serpentine, titanite. 

PotspamM.—J/ornblende /; eight miles from Potsdam, on road to 
Pierrepont, feldspar, tourmaline, black mica, hornblende. 

Rossre (Iron Mines).—arite, hematite, coralloidal aragonite (near 
Somerville), quartz, pyrite, pearl spar; Rosstz Lead Mine, calcite, 
gilenite, pyrite, celesttte, chalcopyrite, hematite, cerussite, anglesite, 
octahedral fluor, black phlogopite ; elsewhere in Rossin, calcite, barite, 
quartz crystals, chondrodite (near Yellow Lake), feldspar! pargastte / 
apatite, pyroxene, hornblende, sphene, zircon, mica, fluorite, serpentine, 
automolite, pearl spar, graphite. 

RussEL.—VPargasite, hematite, quartz (dodec.), calcite, serpentine, 
rensselaerite, magnetite, danburite/ with pyroxene, titanite, biotite, 
hornblende. 

SARATOGA CO.—GREENFIELD.—Chrysoberyl! garnet / tourma- 
line / mica, feldspar, apatite, graphite, aragonite (in iron mines). 
~ SCHOHARIE CO.—BALL’s Cave, and others.—Calcite, stalac- 
tites. 

CARLISLE.—//ibrous barite, cryst. and fibrous calcite. 

ScHoHARIE.—Fibrous celestite, strontianite! eryst. pyrite! 

SULLIVAN CO.—Wurtrzporo’.—Galenite, blende, pyrite, chalco- 

rite. 

ULSTER CO.— ELLENVILLE.— Galenite, blende, chalcopyrite! 
quartz! brookite. 

WARREN CO.—CALDWELL.— Massive feldspar. 

CuEsTer.— Pyrite, tourmaline, rutile, chalcopyrite. 

Diamonp Ise (Lake George).— Calcite, quartz crystals. 

JOHNSBURGH.—Fluorite! zircon! graphite, serpentine, pyrite. 

WASHINGTON CO.—Fort Ann.—Graphite, serpentine. 

GRANVILLE.— Lamellar pyroxene, massive feldspar, epidote. 

WAYNE CO.—Wotcort.—Barite. 

WESTCHESTER CO.—Antuony’s Nosse.—Apatite, pyrite, cal- 
cite/ in large tabular crystals, grouped, and sometimes incrusted 
with drusy quartz. 

CruGERr’s.—White pyroxene, hornblende, magnetite (with green- 
ish spinel), staurolite, fibrolite. 
~ DavEenport’s NEck.—Serpentine, garnet, sphene. 

. EAsTcHesTER.—Blende, pyrite, chalcopyrite, dolomite. 

Hastines.—TZremolite, white pyroxene. 

New RocwELie.—Serpentine, quartz, mica, tremolite, garnet, 
magnesite. 

PEEKSKILL.—Hornblende. 

RyE.—Serpentine, chlorite, black tourmatine, tremolite. 

Sine Sine.—Pyrovene, tremolite, pyrite, beryl, azurite, green 
malachite, cerussite, pyromophite, anglesite, vauquelinite, galenite, 
native silver, chalcopyrite. y 

_---West Farms.—Apatite, tremolite, garnet, stilbite, heulandite, 
chabazite, epidote, sphene. 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 373 


_ YonxKers.—Tremolite, apatite, calcite, analcite, pyrite, tourmaline. 
Yor«ttown.—Fibrolite, monazite, maguetite. 
WYOMING CO.—Wyomine.—Rock salt. 


. NEW JERSEY. 


ANDOVER Iron Mine (Sussex Co.).—Willemite, brown garnet. 
ALLENTOWN (Monmouth Co.).— Vivianite, dufrenite. 
BELLVILLE.—Copper mines. 

BERGEN.—Calciie! datolite! pectolite! analcite, apophyllite! gme- 
linite, prehnite, sphene, stilbite, natrolite, heulandite, laumontite, cha- 
bazite, pyrite, pseudomorphous steatite imitative of apophyliite, 
diabantite. 

Brunswickx.—WNative copper, malachite, mountain leather. 

BryamM.—Chondrodite, spinel, at Roseville, epzdote. 

CANTWELL’sS BripGE (Newcastle Co.).—Vivianite. 

DANVILLE (Jemmy Jump Ridge).—Graphite, chondrodite, augite. 

FLEMINGTON.— Copper mines. 

FRANKFORT.—Serpentine. 

FRANKLIN and STERLING (Sussex Co.).—Spinel! garnet! rhodon- 
ite! willemite! franklinite! zineite! gahnite! hornblende, tremolite, 
chondrodite, white scapolite, black tourmaline, epidote, mica, actinolite, 
augite, sahlite, coccolite, asbestus, jeffersonite (augite), calamine, 
graphite, fluorite, beryl, galenite, serpentine, honey-colored sphene, 
quartz, chalcedony, amethyst, zircon, molybdenite, vivianite, 
tephroite, rhodochrosite, aragonite, sussexite, chalcophanite, roepperite, 
calcozincite, vanuxemite, gahnite, heterolite, pyrochroite. Also al- 
gerite in gran. limestone. 

FRANKLIN and Warwick Mrs.—Py7rvie. 

GRIGGSTOWN and GREENBROOK.—Copper-mines, 

HamBurGH.—One mile north, spinel! tourmaline, phlogopite, horn- 
blende, limonite, hematite. 

HARRISONVILLE (Gloucester Co.).—Amber. 

HopokeEeN.—Serpentine (marmolite), dbrucite, nemalite (or fibrous 
brucite), aragonite, dolomite. 

Hurpstown.—A patite, pyrrhotite, magnetite. 

IMLAYSTOWN.— Vivianite. 

Lockwoop.—Graphite, chondrodite, tale, augite, quartz, green 
spinel, 

MontvitueE (Morris Co.).—Serpentine, chrysotile. 

Muuuica Hii (Gloucester Co.).— Vivianite lining belemnites and 
other fossils. 

NeEwton.——Spinel, blue, pink, and white corundum, mica, vesu- 
vianite, hornblende, tourmaline, scapolite, rutile, pyrite, talc, calcite, 
barite, psewdomorphous steatite. 

Parrerson.— Datolite. 

ROSEVILLE (Sussex Co.).—Fpidote. . 

VERNON.—Serpentine, spinel, hydrotalcite. 

WEEHAWKEN.—Watrolite, anophyllite. 


374 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


PENNSYLVANIA.* 


ADAMS CO.—Gettryspura.—Epidote, fibrous and massive. 

Beprorp Co.—Bridgeport.—Barite. 

BERKS CO.—Morecantown.—At Jones’s mines, 1 m. E. of Mor- 
gantown, malachite, native copper, chrysocolla, magnetite, ailoplane, 
pyrite, chalcopyrite, aurichalcite, melaconite, byssolite, aragonite, 
apatite, talc; 2 m. N. E. from Jones’s mine, graphite, sphene; at 
Steele’s mine, magnetite, micaceous iron, coccolite, brown garnet. 

READING.—Smoky quartz crystals, zircon, stilbite, iron-ore; near 
Pricetown, zircon, allanite, epidote; at Eckhardt’s Furnace, allanite 
with zircon ; at Zion’s Church, molybdenite; near Kutztown, in the 
Crystal Cave, stalactites; at Fritz Island, apophyllite, thomsonite, cha- 
bazite, calcite, azurite, malachite, magnetite, chalcopyrite, stibnite, 
prochlorite, precious serpentine. 

BUCKS CO.—BripGEWwATER Station.—TZitanite. 

BuckInGHAM Townsuip.—Crystallized quartz; near New Hope, 
vesuvianite, epidote, barite. 

SoutHampron.—Near Feasterville, in G@. Vanarsdale’s quarry, 
graphite, pyroxene, sahlite, coccolite, sphene, green mica, calcite, 
wollastonite, glassy feldspar sometimes opalescent, phlogopite, dlue 
quariz, garnet, zircon, pyrite, moroxite, scapolite. 

New Brirain.— Dolomite, galenite, blende, malachite. 

CARBON CQO.—SummitT Hitt, in coal-mines.—Kaolinite. 

CHESTER CO.—AvVonDALE.—Asbestus, tremolite, garnet! opal, 
beryl (yellow)! 

BIRMINGHAM Townsuip.—Amethyst, serpentine. 

East BrRADFORD.—Near Buffington’s bridge, on the Brandywine, 
green, blue, and gray cyanite, gray crystals loose in the soil; farms 
of Dr. Elwyn, Mrs. Foulke, Wm. Gibbons, and Saml. Entrikin, ame- 
thyst ; at Strode’s mill, aquacreptite, oligoclase, drusy quartz, colly- 
rite? on Osborne’s Hill, wad, manganesian garnet (massive), sphene ; 
at Caleb Cope’s lime quarry, fet¢d dolomite, necronite, blue cyanite, 
talc ; near the Black Horse Inn, indurated talc, rutile; on Amos 
Davis’s farm, orthite/ near the paper-mill on the Brandywine, zz'con, 
menaccanite, blue quartz. 

West Braprorp.—Near village of Marshalton, green cyanitte ; at 
the Chester County Poor-house limestone quarry, chesterlite/ on 
dolomite, rutiie/ in acicular crystals, damourite? radiated on dolo- 
mite, quartz crystals. 

CHARLESTOWN.—Lyromorphite, cerussite, galentte, quartz, ame- 
thyst. 

sepsis CovenTRY.—Allanite, near Pughtown black garnets. 

East GosHen.—Serpentine, asbestus, magnetite. 

ELK.—Menaccanite with muscovite, chromite. 

West GosHEN.—On the Barrens, 1 m. N. of West Chester, ser- 
pentine, indurated talc, deweylite, radiated magnesite, aragonite, 
staurolite, asbestus; zotsite on hornblende at West Chester water- 
works (not accessible at present). 


soni also the Report on the Mineralogy of Pennsylvania, by Dr. F. A. Genth, 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 375 


New Garpen.—At Nivin’s limestone quarry, brown and yellow 
tourmaline, necronite, aragonite, fibrolite, kaolinite, tremolite. 

KENNETY.—Actinolite, tremolite; on Wm. Cloud’s farm, sunstone / 
at Pearce’s old mill, sawzstone. 

East Marisoroucu.—On farm of Bailey & Brother, 1 m. S. of 
Unionville, yellow and white tourmaline, chesterlite ; near Marl|bor- 
ough meeting-house, serpentine, 27rcon loose in the soil at Pusey’s 
sawmill, 

West Maritsoroucu.—Near Logan’s quarry, cyanite, yellow 
tourmaline, rutile; near Doe Run village, tremolite: in R. Baily’s 
limestone quarry, 24 m. 8. W. of Unionville, fibrous tremolite, cy- 
anite. 

NEwurn.—14 m. N. E. of Unionville, corundum / often in loose 
crystals with a coating of steatite, diaspore/, spinel (black), picro- 
lite, black tourmaline with flat pyramidal terminations in albite, 
euphyllite, feldspar, beryl/ in one crystal weighing 51 lbs., pyrite, 
chloritoid, diallage, oligoclase ; menaccanite, clinochlore, albite, ortho- 
clase, halloysite, margarite, garnets, beryl; on J. Lesley’s farm, 
corundum, a single mass weighing over 100 tons, diaspore/,; in Ed- 
wards’s limestone quarry, rutile; C. Passmore’s farm, amethyst. 

East NorrincHamM.—Asblestus, chromite in crystals, hallite. 

West NorrincHam.—At Scott’s chrome-mine, chromite, foliated 
talc, marmolite, serpentine, rhodochrome; near Moro Phillips’s 
chrome-mine, asdbestus ; at the magnesia quarry, deweylite, marmo- 
- jite, magnesite, leelite, serpentine, chromite, meerschaum; near Fre- 
mont P. O., corundum. 

West PIKELAND.—In iron-mines near Chester Springs, turgite, 
hematite (stalactitical and in geodes), gothite. 

PENNsBuRY.—On John Craig’s farm, brown garnets, mica; on J. 
Dilworth’s, near Fairville, muscovite/ in Fairville, sanstone ; near 
Brinton’s Ford, chondrodite, sphene, augite ; at Swain’s quarry, or- 
thoclase, muscovite containing magnetite. 

Pocorson.—Farms of J. Entrikin and J. B. Darlington, amethyst, 

Sapspury.—Jutile/ crystals loose for 7 m. along the valley, near 
the village of Parkesburg; near Sadsbury village, amethyst. 

ScHUYLKILL.—In railroad tunnel at PHaNIxvILiE, dolomite /, 
quartz crystals, calcite ; at the WHEATLEY, BROOKDALE, and CHEs- 
TER CountTy LEAD-MINES (now abandoned, and good specimens 
not obtainable), 14 m. 8S. of Pheenixville, pyromorphite! cerussiie! 
galentte, anglesite/ quartz crystals, chalcopyrite, barite, jfluortte 
(white), stolzite, wulfenite! calamine, vanadinite, blende! mimetite / 
descloizite, géthite, chrysocolla, native copper, malachite, azurite, 
limonite, calcite, sulphur, pyrite, melaconite, pseudomalachite, gers- 
dorffite, chalcocite ? covellite. 

WILLISTOWN.—Magnetite, chromite. 

West Town.—On the serpentine rocks, 3 m. 8. of West Chester, 
clinochlore! jefferisite / actinolite. 

West WHITELAND.—At Gen. Trimble’s iron-mine (southeast), 
stalactitic hematite! wavellite! / in radiated stalactites, gibbsite. 

WaARwWICK.—Elizabeth mine and Keim’s mine 1 m. N. of Knauer- 
town, aplome garnet! micaceous hematite, pyrite (octahedral), chal- 
copyrite massive and in crystals, magnetite, brown garnet, calcite, 


376 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


byssolite/ serpentine; near village of St. Mary’s, magnetite (dode- 
cahedral), melanite, garnet, actinolite ; at Hopewell iron-mine, 1 m. 
N. W. of St. Mary’s, magnetite in octahedral crystals. 

YELLOW SprinGs.—Allanite. 

DAUPHIN CO.—NrEsar HuMMErstown.—Green garnets, cryst. 
smoky quartz, feldspar. 

DELAWARE CO.— Aston Townsuip.— Amethyst, corundum 
. (Village Green), fidrolite, black tourmaline, margarite, sunstone, asbes- 
tus, anthopyllite, steatite; Bridgewater Station, Zvlanite, in twins 
and translucent; at Peter’s mill-dam in the creek, pyrope garnet. 

BrrMINGHAM.—Jfi5rolite, kaolin (abundant), rutile, amethyst ; at 
Bullock’s old quarry, zircon, bucholzite. 

CuHESTER.—Amethyst, black tourmaline, beryl, crystals of orthoclase, 
beryl, garnet, molybdenite, molybdite, uraninite, muscovite. 

CHICHESTER.—Near Trainer’s mill-dam, deryl, tourmaline, feldspar. 

ConcorD.—WMica, feldspar, kaolin, drusy quartz, garnet, antho- 
phyllite, fibrolite, amethyst, manganesian garnet, meerschaum; in 
Green’s creek, pyrope garnet. 

Darsy.—Dlue and gray cyanite, beryl, garnet, smoky quartz. 

EpcEemMontT.—Amethyst; 1 m. E. of Edgemont Hall, vwttle in 

uartz. 
z LEIPERVILLE.—Garnet, zoisite, heulandite, leidyite, beryl (De- 
shong’s qu.), black tourmaline. 

MArRPLE.— Tourmaline, andalusite, amethyst, actinolite, bronzite, 
talc, radiated actinolite in talc, chromite, beryl, menaccanite tn quartz, 
amethyst. 

MIDDLETOWN.—Amethyst, beryl, black mica, mica dendritic with 
magnetite, manganesian garnets / some 3 inches in diameter, indurated 
tale, rutile, mica, green quartz! anthophyllite, radiated tourmaline, stau- 
rolite, titanic iron, fibrolite, serpentine; at Lenni, chlorite, green and 
bronze vermiculite! green feldspar; at Mineral Hill, crystals of corwn- 
dum, some of 6 inches, actinolite, bronzite, green feldspar, moonstone, 
sunstone, magnesite, chromite (octahedrons), columbite, bery/, asbestus, 
rutile, melanosiderite, hallite; at Painter’s Farm, z7rcon with oligoclase, 
tremolite, tourmaline; at Hibbard’s Farm and at Fairlamb’s Hill, chro- 
mite in brilliant octahedrons; John Smith farm, meerschaum. 

NEwTown.—Serpentine, hematite, enstatite. 

UPPER PROVIDENCE.—Anthophyllite, radiated asbestus, andalusite, 
radiated actinolite, tourmaline, beryl, green feldspar, amethyst (one of 77 
lbs. from Morgan Hunter’s farm), andalusite/ ; at Blue Hill, blue 
quartz in chlorite, amianthus in serpentine. 

LOWER PROVIDENCE.— Amethyst, garnet, feldspar ! (large crystals). 

Ravnor.— Garnet, marmolite, deweylite, chromite, asbestus, mag- 
nesite, picrolite, bronzite. 

SPRINGFIELD.—Andalusite, tourmaline, beryl, titanic iron, garnet; 
on Fell’s Laurel Hill, beryl, garnet; near Lewis’s paper-mill, allophane, 
mica, albite. 

W ATERVILLE.—Near Chester and Upland, chabazite. 

FRANKLIN CO.—LANcAsTER StTatron.—Barite. 

HUNTINGDON CO.—Near FranKstown.—In a bed of a stream 
and on a hill-side, fibrous celestite, quartz crystals. 

LANCASTER CO.—DRrumorE Townsuip.—Quartz crystals. 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 377 


Fciron.—At Wood’s chrome mine, near Texas, brucite / zaratite 
(emerald nickel), pennite/ ripidolite! kimmererite! enstatite, bronzite, 
baltimorite, chromite, williamsite, chrysolite! marmolite, picrotite, hy- 
dromagnesite, dolomite, magnesite, aragonite, calcite, serpentine, hem- 
atite, menaccanite, genthite, chrome-garnet, bronzite, millerite; at 
Low’s mine, hydromagnesite, bructte (lancasterite), picrolite, magnesite, 
williamsite, chromic tron, talc, zaratite, baltimorite, serpentine, hema- 
tite; on M. Boice’s farm, 1 m. N. W. of village, pyrite, enstatite; near 
Rock Springs, chalcedony, carnelian, moss agate, green tourmaline in 
tale, titanic iron, chromite, octahedral magnetite in chlorite; at Rey- 
nolds’s old mine, calcite, talc, picrolite, chromite; at Carter’s chrome 
mine, brookite. 

Gap Mrynes.—Chalcopyrite, pyrrhotite (niccoliferous), miillerite 
(botryoidal radiations), vivianite/ actinolite, siderite, hisingerite, 
pyrite. 

wen VautiEy.—8 m. §S. of Lancaster, argentiferous galenite, 
vauquelinite, rutile at Pequea mine; 4 m. N. W. of Lancaster, cala- 
mite, galenite, blende; pyrite in cubes near Lancaster; at the Lancaster 
zinc mines, calamine, blende, tennantite? smdthsonite (pseud. of dolo- 
mite), aurichalcile. 

LEBANON CO.—Cornwatuu.—Magnetite, pyrite (cobaltiferous), 
chalcopyrite, native copper, azurite, malachite, chrysocolla, cuprite (hy- 
drocuprite), allophane, brochantite, serpentine, quartz pseudomorphs; 
galenite (with octahedral cleavage), fluorite, covellite, hematite (mica- 
ceous), cpal, asbestus. 

LEHIGH CO.—FRIeEpEnsvILLE.—At zinc mines, calamine, smith- 
sonite, hydrozincite, massive blende, greenockite, quartz, allophane, 
mountain leather, aragonite, sauconite; near Allentown, magnetite, 
pipe-iron ore; near BethIchem, on 8. Mountain, allanite, with zircon, 
magnetite, martite, black spine], tourmaline, chalcocite. 

SHIMERVILLE.—Corundum. 

LUZERNE CO.—Scrantron.—Under peat, phytocollite. 

DriFrton.—Pyrophyilite. 

MIFFLIN CO.—Strontianite. 

MONROE CO.—In CHERRY VALLEY, calcite, chalcedony, quartz; 
in Poconac Valley, near Judge Mervine’s, cryst. quartz. 

MONTGOMERY CO.—ConsHonockEen.—Fibrous tourmaline, me- 
naccanite, aventurine quartz, phyllite; in the quarry of Geo. Bullock, 
calcite in hexagonal prisms, aragonite. 

LowER PRovIDENCE.—Perkiomen lead and copper mines, near 
village of Shannonville, azurite, blende, galenite, pyromorphite, cerus- 
site, wulfenite, anglesite, barite, calamine, chalcopyrite, malachite, 
chrysocolla, brown spar, cuprite, covellite (rare), melaconite, libethen- 
ite, pseudomalachite. 

Waitt Marsn.—D. O. Hitner’s iron mine, limonite in geodes and 
stalactites, géthite, pyrolusite, wad, lepidocrocite; at Edge Hill Street, 
North Pennsylvania Railroad, titanic iron, braunite, pyrolusite; 1 m. 
S. W. of Hitner’s iron mine, limonite, turgite, géthite, pyrolusite, velvet 
manganese, wad; near Marble Hall, at Hitner’s marble quarry, white 
marble, granular barite, resembling marble; at Spring Mills, limonite, 
pyrolusite, gothite; at Flat Rock Tunnel, opposite Manayunk, stilbite, 
heulandite, chabasite, ilvaite, beryl, feldspar, mica. 


378 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


LAFAYETTE, at the Soapstone quarries.—Talc, jefferisite, garnet, 
albite, serpentine, zoisite, staurolite, chalcopyrite; at Rose’s Serpentine 
quarry, opposite Lafayette, enstatite, serpentine. 

NORTHAMPTON CO.—BeEtHLEnEM.—Axinite, zircon (2m. N.). 

BusuHxiuu T.—Crystal Spring on Blue Mountain, quartz crysials. 

NAZARETH.—Quartz crystals. 

Near Easton.—Zircon / (exhausted), nephrite, coccolite, tremolite, 
pyroxene, sahlite, limonite, magnetite, purple calcite, bowenite. 

WitiiAMs Townsuip.—Pyrolusite in geodes in limonite beds, 
gothite (lepidocrocite) at Glendon. 

NORTHUMBERLAND CO.—Opposite SELIN’s GrovE.—Cala- 
mine. 

PHILADELPHIA CO.—FRANKFoRD.—Titanite in gneiss, apo- 
phyllite; at the quarries on Frankford Creek, stilbite, molybdenite, 
hornblende; on the Connecting Railroad, wad, earthy cobalt; at Chest- 
nut Hill, magnetite, green mica, chalcopyrite, fluorite. 

FarrmMount Watrr-Worxks.—In quarries opposite Fairmount, 
autuntte! torbernite, orthoclase, beryl, tourmaline, albite, wad, menac- 
canite. 

Gore@as’s and CREASE’s LANE.—Tourmaline, cyanite, staurolite, 
hornstone, fahlunite. 

Near GERMANTOWN.—Black tourmaline, laumontite, apatite; York 
Road, tourmaline, beryl. 

Hert’s Miti.—Alunogen, tourmaline, cyanite, titanite. 

MaAnayunk.—At the soapstone quarries above Manayunk, talc, 
steatite, chlorite, vermiculite, anthophyllite, staurolite, dolomite, apa- 
tite, asbestus, brown spar, epsomite. 

MEAGARGEE’S Paper-mill.—Staurolite, titanic iron, hyalite, apatite, 
grecn mica, iron garnets in abundance. 

McKInney’s QuARRY, on Rittenhouse Lane.—Feldspar, apatite, 
stilbite, natrolite, heulandite, epidote, hornblende, bornite, malachite. 

ScHUYLKILL FAaLuis.—Chabazite, titanite, fluorite, epidote, musco- 
vite, tourmaline, prochlorite. 

SCHUYLKILL CO.—Tamagqva, near PoTTsvILLB, in coal-mines. 
— Kaolinite. 

Near Mananoy Crry.—Pyrophyllite, alunogen, copiapite, in coal- 
mines. 

YORK CO.—Bornite, rutile in slender prisms in granular quartz. 


DELAWARE. 


NEWCASTLE CO.—BRrANDYWINE SPRINGS. —/tbrolite abundant, 
sahlite, pyroxene; Brandywine Hundred, muscovite, enclosing reticu- 
jated magnetite, garnet. 

Drxon’s FeLpDsPAR QUARRIES, 6 m. N. W. of Wilmington (not 
open).— Beryl, apatite, cinnamon-stone / magnesite, serpentine, asbes- 
tus, black towrmatine / cyanite. 

EASTBURN’S LIMESTONE QUARRIES, near the Pennsylvania line.— 
Tremolite, bronzite. 

QUARRYVILLE.—Garnet, fibrolite. 

Near NEWARK, on the railroad.—Spherosiderite on drusy quartz, 
jasper (ferruginous opal), cryst. siderite in cavities of cellular quartz, 
quartz crystals loose in soil. ; 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 379 


Way’s Quarry, 2 m. S. of Centreville-—/eldspar in cleavage 
masses, apatite, mica, deweylite, granular quartz. 
ILMINGTON.—In Christiana quarries, hypersthene. 
KENNETT TURNPIKE, near Centreville.—Cyanite and garnet. 
KENT CO.—Near MippLetown, Polk’s marl-pits, vivianite/ 
SUSSEX CO.—Near Care HENLOPEN.—Vivianite. 


MARYLAND. 


BALTIMORE (Jones’s Falls, 12 mile from B.).—Chabazite (hayden- 
ite), heulandite (beaumontite), pyrite, siderite, mica, stilbite. 

16 m. from Baltimore, on the Gunpowder, graphite; 23 m. from 
B., on the Gunpowder, fa/c; 25 m. from B., on the Gunpowder, 
magnetite, sphene, pycnite; 8 to 20m. N. of B., in limestone, tremo- 
lite, augite, pyrite, brown and yellow tourmaline; 15 m. N. of B., 
sky-blue chalcedony in granular limestone; 18m. N. of B., at Scott’s 
mills, magnetite, cyanite. 

BarE Hiuxus.—Chromite, asbestus, tremolite, talc, hornblende, ser- 
pentine, chalcedony, meerschaum, baltimorite, chalcopyrite, magnetite, 
enstatite, bronzite. 

CAPE SABLE, near Magothy R.—Amber, pyrite, alum slate. 

CARROLL Co.—Near Sykesville, Liberty Mines, gold, magnetite, 
pyrite (octahedrons), chalcopyrite, \inneite (carrollite); at Patapsco 
Mines, near Finksburg, bornite, malachite, siegenite, linnaite, reming- 
tonite, magnetite, chalcopyrite ; at Mineral Hill mine, bornite, chalco- 
pyrite, linnzite, gold, magnetite. 

Crcrt Co., north part.— Chromite in serpentine. 

Cooptown, Hartford Co.—Olive-colored tourmaline, diallage, tale 
of green, blue, and rose colors, ligniform asbestus, chromite, serpentine. 

DEER CREEK.—Mcagnetite / in chlorite slate. 

FREDERICK Co.—Old Liberty minc, near Liberty Town, black cop- 
per, malachite, chalcocite, hematite; at Dollyhyde mine, dornite, chal- 
copyrite, pyrite, argcntiferous galenite in dolomite. 

MonTGoMERY Co.—Ozide of manganese. 

SomERsET and WorcEsTrER Cos., N. part.—Bog-ore, vivianite. 

St. Mary’s Rrver.—Gypsum / in clay. 

PYLESVILLE, Hartford Co.—Asbestus mine. 


VIRGINIA, WEST VIRGINIA, AND DISTRICT OF 
3 COLUMBIA. 


ALBEMARLE Co., a little west of the Green Mts.—Steatite, graphite, 
galenite. 

AMELIA Co.—Near Court House, mica! orthoclase, microlite! 
columbite, orthite, helvite, topazolite, amethyst, fluorite, apatite. 

AmueErst Co.—Along the west base of Buffalo Ridge, copper ores ; 
on N. W. slope of Friar Mtn., allanite, magnetite, zircon. 

Avuausta Co.—At Weyer’s (or Weir’s) cave, calcite, stalactites. 

BuckINGHAM Co.—Gold at Garnett and Moseley mines, also, pyrite, 
pyrrhotite, calcite, garnet; at Eldridge mine (now London and Vir- 
ginia mines) near by, and the Buckingham mines near Maysville, gold, 
auriferous pyrite, chalcopyrite, tennantite, barite ; cyanite, tourmaline, 
actino lite, 


380 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


CHESTERFIELD Co.—Near this and Richmond Co., bituminous coal, 
native coke. At Manchester, diamond. 

CULPEPPER Co., on Rapidan River.—Gold, pyrite. 

FRANKLIN Co.—Grayish steatite. 

Fauquier Co., Barnett’s mills.—Asbestus, gold mines, barite, cal- 
cite. . 

FLuvANNA Co.—Gold at Stockton’s mine; also tetradymite, at 
“Tellurium mine.” 

PuHenrx Coprper Mrnus.—Chalcopyrite, etc. 

GoocHLAND Co.—Gold mines (Moss and Busby’s). 

HARPER’S FERRY, on both sides of the Potomac.—Thuringite 
(owenite) with quartz. 

JEFFERSON Co., at Shepherdstown.—Fluor. 

KANAWHA Co.—At Kanawha, petroleum, brine springs, cannel coal. 

Loupon Co.— Tabular quartz, prase, pyrite, tale, chlorite, soapstone, 
asbestus, chromite, actinolite, quartz crystals ; micaceous tron, bornite, 
malachite, epidote, near Leesburg (Potomac mine). 

LovisA Co.—Walton gold mine, gold, pyrite, chalcopyrite, argen- 
tiferous galenite, siderite, blende, anglesite; boulangerite, blende (at 
Tinder’s mine); corundum (40 m. N. of Richmond). 

Nxrxson Co.—Galenite, chalcopyrite, malachite. ; 

ORANGE Co.—Western part, Blue Ridge, hematite; gold at the 
Orange Grove and Vaucluse gold mines, worked by the “ Freehold ” 
and ‘‘ Liberty” Mining Companies. 

ROCKBRIDGE Co.—3 m. 8. W. of Lexington.—Barite, dufrenite, in 
bed 10 in. thick, with strengite. 

SHENANDOAH Co., near Woodstock.—Fluorite. 

SPoTTSYLVANIA Co., 2 m. N. E. of Chanccllorsville.—Cyanite ; 
gold-mines at the junction of the Rappahannock and Rapidan ; on 
the Rappahannock (Marshall mine); Whitehall mine, affording also 
tetradymite. 

STAFFORD Co., 8 or 10 m, from Falmouth.—Micaceous iron, gold, 
tetradymite, silver, galenite, vivianite. 

WASHINGTON Co.—18 m. from Abingdon.—Halite, gypsum. 

WrtuHe Co. (Austin’s mines).—Cerussite, miniwm, plumbie ochre, 
blende, calamine, galenite, graphite, aragonite. 

On the Potomac, 25 m. N. of Washington,—Swulphur in limestone. 


NORTH CAROLINA. 


ALEXANDER Co.—At Stony Point, spodumene var. hiddenite / beryl! 
emerald! rutile (in quartz), monazite, allanite, quartz, smoky quartz. 
At White Plains, quartz crystals, hiddenite, beryl, rutile, columbite, 
tourmaline, scorodite. At Milholland’s mill, rwttle, monazite, musco- 
vite, quartz. 

BuNcoMBE Co.—In the mica mines, muscovite ! orthoclase ! garnet ; 
at Swannanda Gan, corundum in cyanite. 

BurKE Co.—Gold, monaziie, zircon, beryl, corundum, garnet, 
sphene, smoky quartz, graphite, iron ores, tetradymite, montanite; in 
gravels at Brindletown, octahedrite, brookite, zircon, fergusonite, mona- 
zite, xenotime (twinned with zircon), samarskite garnet, tourmaline, 
magnetite; Linville Mtn., itacolumyte. 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 381 


CaBarrus Co.—Phenix Mine, gold, barite, chalcopyrite, auriferous 
covellite, pyrite, quartz pseudomorph after barite, tetradymite, mon- 
tanite; Pioneer mines, gold, limonite, pyrolusite, barnhardtite, wolfram, 
scheelite, cuprotungstite, tungstite, diamond, chrysocolla, chalcocite, 
molybdenite, chalcopyrite, pyrite ; White mine, needle ore, chalcopy- 
rite, barite; Long and Muse’s mine, argentiferous galenite, pyrite, 
chalcopyrite, limonite; Boger mine, tetradymite; Fink mine, valuable 
copper ores; McMakin’s, tetrahedrite, argentite, barite, magnetite, 
tale, blende, pyrite, proustite, galenite, pyrolusite; Bangle mine, 
scheelite. 

CALDWELL Co.—Chromite, beryl, garnet; near Patterson, serpen- 
tine. 

CATAWBA Co.— Garnet, smoky quartz. 

CHATHAM Co.—Mineral coal, pyrite, chloritoid, bornite, chalcopy- 
rite, rutile in quartz, muscovite, pyrophyllite (slaty). 

CHEROKEE Co.—Near Valley River, tremolite, tale (white steatite), 
marble of various colors, limonite ; staurolite (Parker minc). 

CLEVELAND Co.—White Plains, guartz crystals, smoky quartz, tour- 
maline, rutile in quartz. 

CuLay Co.—At the Cullakenee mine and elsewhere, corundum (pink), 
zoisite, tourmaline, margarite, willcoxite, dudleyite, picrolite; Tus- 
quitee Cr., staurolite; at Shooting Creek, chrysolite. 

Davipson Co.—King’s, now Washington mine, native silver, cerus- 
site, anglesite, scheelite, pyromorphite, galenite, blende, malachite, 
black copper, wavelliie, garnet, stilbite; 5m. from Washington mine, 
en Faust’s farm, gold, tetradymite, oxide of bismuth and tellurium, 
montanite, chalcopyrite, limonite, siderite, epidote; near Squire 
Ward's, gold in crystals, electrum. 

FRANKLIN Co.—At Partiss mine, diamond. 

Gaston Co.—lIron ores, corundum, margarite; near Crowder’s 
Mountain (in what was formerly Lincoln Co.), lazulite, eyanite, garnet, 
corundum, rutile, margarite, graphite; also 20 m. N. E., near S. end 
of Clubb’s Mountain, lazulite, cyanite, talc, rutile, topaz, pyrophyllite, 
corundum; King’s Mountain (or Briggs) mine, native tellurium, 
altaite, nagyagite, tetradymite, montanite, corundum, sphalerite. 

GuILFoRD Co.—McCulloch copper and gold mine, 12 m. from 
Greensboro’, gold, pyrite, chalcopyrite (worked for copper), quartz, sid- 
erite; at Deep River, compact pyrophyliite (worked for slate-pencils); 
at Gibsonville, green quartz. 

Haywoop Co.—Corundum, margarite, damourite; Caster mine, 
corundum. 

HENDERSON Co.—Zircon, sphene (xanthitane). 

IREDELL Co.—Statesville, corundum enveloped in margarite, quartz 
crystals, eyanite, actinolite. 

JACKSON Co.—Alunogen? at Smoky Mountain; at Webster, serpen- 
tine, chromite, genthite, enstatite, chrysoliie, talc; Hogback Mountain, 
pink corundum, margarite, tourmaline. 

Lixcotn Co.—Diamond; at Randleman’s, amethyst, rose quartz, 
graphite. 

Macon Co.—Near Franklin, Culsagee and other mines; corundum / 
spinel, diaspore, chromite, chrysolite, talc, enstatite, tremolite, tour- 
maline, damourite, prochlorite, culsageeite, kerrite, maconite; Jenk’s 


382 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


mine, corundum! ; Thorn Mtn., beryl; in the mica mines, diotite in 
muscovite. 

_McDoweEt. Co.—Brookite, monazite, corundum in small red and 
white crystals, pyrophyllite, zrcons, garnet, beryl, sphene, xenotime, 
rutile, iron ores, pyromelane, tetradymite, montanite. 

Mapison Co.—20m. from Asheville, corundum, margarite, chlorite; 
Carter’s mine, beryl; staurolite. 

MrcKLenBurRG Co.—Near Charlotte (Rhea and Cathay mines) and 
elsewhere, chalcopyrite, gold, zircon ; chalcotrichite at McGinn’s mine; 
barnhardtite near Charlotte; pyrophyllite in Cotton Stone Mountain, 
diamond; Flowe mine, scheelite, wolframite; Todd’s Branch, mona- 
gite, diamond. . 

MircHeLt Co.—At the Wiseman mica mine, muscovite! samars- 
kite / hatchettolite, euxenite, columbite, rogersite, wraninite, uranotile, 
allanite, beryl, zoisite, garnet, menaccanite, gummite, wraconite, fer- 
gusonite, torbernite, autunite; at Grassy Creek mine, muscovite, beryl, 
samarskite ; at Deake mine, gahnite, mica, monazite! uraninite, 
uranotile, gummite, uranochre; near Bakersville, chrysolite. 

MontTcoMERY Co.—Steele’s mine, Cotton Stone Mtn., ripidolite, 
albite, pyrophyllite. 

Moore Co.—Carbonton, compact pyrophyllite (large beds on Lin- 
ville Mtn.). 

ORANGE Co.—At Hillsboro’, pyrophyllite. 

Ranvo.tpu Co.—At Pilot Knob, pyrophyliite. 

Rowan Co.—Gold Hill mines, 388 m. N. E. of Charlotte, and 14 m. 
from Salisbury, gold, auriferous pyrite; 10 m. from Salisbury, feldspar 
in crystals, bismuthinite. 

RUTHERFORD Co.—Gold, graphite, bismuthic gold, diamond, eu- 
clase, pseudomorphous quartz? chalcedony, corundum in small 
crystals, epidote, pyrope, brookite, zircon, monazite, rutherfordite, 
samarskite, quartz crystals, itacolumyte; on the road to Cooper’s Gap, 
cyanite. 

avn Co.—Lemmond gold mine, 18 m. from Concord (at Stewart’s 
and Moore’s mine), gold, blende, argentiferous galenite, pyrite, chal- 
copyrite. 

WaAkE Co.—Graphite. 

Wartauea Co.—At Rich Mtn., chrysolite, chromite. 

YANCEY Co.—Zlron ores, amianthus, chromite, chrysolite, garnet 
(spessartite), cyantte, samarskite, columbite, corundum, spinel; at Ray 
mica mine, muscovite, tantalite (columbite), monazite, beryl, garnet, 
zircon, rutile; at Hampton’s, chromite, epidote, enstatite, tremolite, 
chrysolite, serpentine, tale, magnesite. 


SOUTH CAROLINA. 


ABBEVILLE Co.—Oakland Grove, gold (Dorn mine), galenite, pyro- 
morphite, amethyst, garnet. 

AND=RSON Co.—At Pendleton, actinolite, galenite, kaolin, towrma- 
line, zircon. 

CHEOWEE VALLEY.—Galenite, tourmaline, gold. 

CHESTERFIELD Co.— Gold (Brewer’s mine), talc, chlorite, pyrophyl- 
lite, pyrite, native bismuth, bismuth carbonate, red and yellow ochre, 
whetstone, enargite. 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 383 


GREENVILLE Co.—Galenite, pyromorphite, kaolin, chalcedony in 
buhrstone, beryl, plumbago, epidote, tourmaline. 

KerrsHaw Co.—Rutile. 

LANCASTER Co.—Gold (Hale’s mine), talc, chlorite, cyanite, ita- 
columyte, pyrite; gold also at Blackman’s mine, Massey’s mine, 
Ezell’s mine. 

LAURENS Co.—Corundum, damourite. 

NEWBERRY Co.—Leadhillite. 

Pickens Co.—Gold, manganese ores, kaolin. 

RicHLAND Co.—Chiastolite, novaculite. 

SPARTANBURG Co.—Magnetite, chalcedony, hematite ; at the Cow- 
pens, limonite, graphite, limestone, copperas ; Morgan mine, leadhill- 
ite, pyromorphite, cerussite. 

Union Co.—Fairforest gold-mines, pyrite, chalcopyrite. 

-YorK Co.—Whetstone, witherite, barite, tetradymite. 


GEORGIA. 


BURKE AND ScrIvEN Cos.—Hyalite. 

CHEROKEE Co.—At Canton Mine, chalcopyrite, galenite, claustha- 
lite, plumbogummite, hitchcockite, arsenopyrite, lanthanite, harrisite, 
cantonite, pyromorphite, automolite, zinc, staurolite, cyanite; at Ball- 
Ground, spodumene. 

CuaARK Co., near Clarksville.—Gold, xenotime, zircon, rutile, cyanite, 
hematite, garnet, quartz. 

Fannin Co.—Siaurolite/ chalcopyrite. 

HABERSHAM Co.—Grold, pyrite, chalcopyrite, galenite, hornblende, 
garnet, quartz, kaolinite, soapstone, chlorite, rutile, iron ores, tourma- 
line, staurolite, zircon. 

Hau Co.—Gold, quartz, kaolin, diamond. 

HEARD Co.—Molybdite, quartz. 

LEE Co.—At the Chewacla Lime Quarry, dolomite, barite, quartz 
crystals. 

Lincotn Co.—Laeulite! rutile! hematite, cyanite, menaccanite, 
pyrophyllite, gold. 

LOwNDEs Co.—Corundum. 

Lumpkin Co.—At Field’s gold-mine, near Dahlonega, gold, tetrady- 
mite, pyrrhotite, chlorite, menaccanite, allanite, apatite. 

RapBwun Co.—Gold, chalcopyrite, muscovite, beryl, corundum. 

SPAULDING Co.—Tetradymite. 

WASHINGTON Co., near Saundersville.— Wavellite, fire opal. 

WuitE Co.—Racoochee Valley, diamond. 


ALABAMA. 


Brss Co., Centreville.—Jron ores, marble, barite, coal, cobalt. 

CHAMBERS Co.—Near La Fayette, steatite, garnets, actinolite, chlo- 
rite; east of Oak Bowery, steatite. 

Cuitton Co.—Muscovite, graphite, limonite, rutile. 

CLEBURNE Co.—At Arbacoochee mine, gold, pyrite, and three miles 
distant cyanite, garnets; at Wood’s mine, black copper, azurite, chalco- 
pyrite, pyrite. 


884 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. ' 


Cray Co.—Steatite, magnetite; near Delta and Ashland, muscovite. 

Coosa Co.—Tantalite, gold, muscovite, cassiterite, rutile, mica; near 
Bradford, zircon, corundum, asbestus; near Rockford, tanialite. 

RanpouPH Co.—Gold, pyrite, tourmaline, muscovite; at Louina, 
porcelain clay, garnet. 

TALLADEGA Co.—Limonite. 

TALLAPOOSA Co., at Dudleyville.— Corundum, margarite, ripidolite, 
spinel, tourmaline, actinolite, steatite, asbestus, chrysolite, damourite, 
corundum altered to tourmaline (containing a nucleus of corundum), at 
Dudleyville, dudleyite. 

TuscaLoosa Co.—Coal, galenite, pyrite, vivianite, limonite, calcite, 
dolomite, cyanite, steatite, quartz crystals, manganese ores. 


FLORIDA. 


Near Tampa Bay.—Limestone, sulphur springs, chalcedony, 
agate, szlicified shells and corals. 


KENTUCKY. 


ANDERSON Co.—Galenite, barite. 

Cuinton Co.—Geodes of quartz. 

CRITTENDEN Co.—Galenite, fluorite, calcite. 

CUMBERLAND Co.—At Mammoth Cave, gypsum rosettes! calcite, 
stalactites, nitre, epsomite. 

a ie Co.—6 m. N. E. of Lexington, galenite, barite, witherite, 
blende. 

Livineston Co., near the line of Union Co.—Galenite, chalcopyrite, 
large vein of fluorite. 

MeERcER Co.—At McAfee, fluorite, pyrite, calcite, barite, celestite. 

OwEN Co.—Galenite, barite. 


TENNESSEE. 


Brown’s CREEK.—Galenite, blende, barite, celestite. 

CLAIBORNE Co.—Calamite, galenite, smithsonite, chlorite, steatite, 
magnetite. 

CockE Co., near Bush Creek.—Cacoxenite? kraurite, iron sinter, 

- stilpnosiderite, brown hematite. 

Davipson Co.—Selenite, with granular and snowy gypsum, or ala- 
baster, crystallized and compact anhydrite, jluorite in crystals? calcite 
in crystals. Near Nashville, blue celestite (crystallized, fibrous, and 
radiated), with dardte in limestone. Haysboro’, galenite, blende, with 
barite as the ganguc of the ore. 

Dickson Co.—Manganite. 

JEFFERSON Co.— Calamine, galenite, fetid barite. 

Knox Co.—Magnesian limestone, native iron, variegated marbles | 

Maury Co.— Wavellite in limestone. 

Pouxk Co., Ducktown mines, 8S. E. corner of State.—Melaconite, 
chalcopyrite, pyrite, native copper, bornite, rutile, zozsite, galenite, 
harrisite, alisonite, blende, pyroxene, tremolite, sulphates of copper and 
tron in stalactites, allophane, rahtite, chalcocite (ducktownite), chal- 
cotrichite, azurite, malachite, pyrrhotite, limonite. i 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 385 


Roan Co., E. declivity of Cumberland Mts.—Wavellite in lime- 
stone. 

SEvIER Co., in caverns.—Epsomite, soda alum, nitre, nitrate of 
calcium, breccia marble. 

SmirH Co.—Fluorite. 

Smoxy Mr., on declivity.—Hornblende, garnet, staurolite. 


OHIO. 


BAINBRIDGE (Copperas Mt., a few miles east of B.).—Calcite, barite, 
pyrite, copperas, alum. 

CANFIELD and PoLanp.— Gypsum / 

LAKE Erte.—Strontian Island, celestite / Put-in-Bay Island, celestite / 
sulphur !/ calcite. 


MICHIGAN. 


Bresr (Monroe Co.).— Calcite, amethystine quartz, apatite, celestite. 

GranpD MAarats.—Thomsouite (lintonite). 

GRAND Rapips.—Sélenite, fib. and granular gypsum, calcite, dolo- 
mite, anhydrite. 

LAKE SuPERIOR Mrntne Recion.—The copper-mines are mostly 
between Keweenaw Point and Portage Lake. The copper occurs in 
the trap or amygdaloid, and in the associated conglomerate ; and in 
the latter (which is the rock of the Calumet and Hecla mine) the ore is 
distributed finely through the mass of the rock. ative copper! native 
silver ! chalcopyrite, horn silver, tetrahedrite, manganese ores, epidote, 
prehnite, laumont.te, datolite, heulandite, orthoclase, analcite, chabazite, 
compact datolite, chrysocolla, mesotype (Copper Falls mine), Jeon- 
hardite (ib.), analcite (ib.), apophyllite (at Cliff mine), wollastonite (ib.), 
calcite, guartz (in crystals at Minnesota mine), compact datolite, or- 
thoclase (Superior mine), saponite, melaconite (near Copper Harbor, 
but exhausted), chrysocolla; on Chocolate River, galenite and sul- 
phide of copper; chalcopyrite and native copper at Presque Isle; at 
Albion mine, domeykite; at Prince Vein, barite, calcite, amethyst; at 
Albany and Boston mine, Portage Lake, prehnite, analcite, orthoclase, 
cuprite; at Sheldon location, domeykite, whiineyite, algodoniie; Quincy 
mine, calcite, compact datolite. At the Spur Mountain iron-mine 
(magnetite), chlorite pseudomorph after garnet; Isle Royale, datolite, 
prehnite. 

MARQUETTE.—Manganite, galenite; 12 m. W., at Jackson Mt., and 
other mines, hematite, limontie, géthite / magnetite, jasper. 

Monroxr.—Aragonite, apatite. 

NEGAUNEE.—Manganite, githite, hematite, barite, kaolinite. 

Pornt Avux PEAux (Monroe Co.).—Amethystine quartz, apatite, 
celestite, calcite. 

Sacrnaw Bay.—At Alabaster, gypsum. 

ieee Pornt (Monroe Co.).—Apatite, amethystine quartz, celestite, 
calcite. 


ILLINOIS. 


GALLATIN Co., on a branch of Grand Pierre Creek, 16 to 80 m. 
from Shawneetown, down the Ohio, and from half to eight miles from 


20 


386 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


this river.— Violet fluorite / in Carboniferous limestone, barite, galenite, 
blende, limonite. 

Hancock Co.—At Warsaw, quartz geodes containing calcite! chal- 
cedony, dolomite, blende/ brown spar, pyrite, aragonite, gypsum, bitu- 
men. 

Harpin Co.—Near Rosiclare, calcite, galenite, blende ; 5 m. back 
from Elizabethtown, bog-iron ; one mile north of the river, between 
Elizabethtown and Rosiclare, nitre. 

Jo Daviess Co.—At Galena, galenite, calcite, pyrite, blende; at 
Marsden’s diggings, galenite! blende, cerussite, marcasite in stalactitic 
forms, pyrite. 

Quincy.— Calcite! pyrite. 

ScaLtes Mounp.—Barite, pyrite. 


INDIANA. 


LIMESTONE CAVERNS; Corydon Caves, etc.—Hpsom salt. 

In most of the southwest counties, pyrite, tron sulphate, and 
feather alum ; on Sugar Creek, pyrite and ¢ron sulphate; in sand- 
stone of Lloyd Co., near the Ohio, gypsum, at the top of the blue 
limestone formation, brown spar, calcite. 

LAWRENCE Co.— Kaolinite (= indianaite), Allophane, limonite. ~ 


MINNESOTA. 


NortH SHoreE or L. Superior (range of hills running nearly 
N. E. and 8. W., from Fond du Lac Supérieure to the Kamanisti- 
queia River on Thunder Bay).—Scolecite, apophyllite, prehnite, stilbite, 
laumontite, heulandite, harmotome, thomsonite (much of it in loose 
pebbles on shore of L. Sup., between Terrace Point and Poplar 
River), fluorite, barite, tourmaline, epidote, hornblende, calcite, quartz 
crystals, pyrite, magnetite, steatite, blende, black oxide of copper, 
malachite, native copper, chalcopyrite, amethystine quartz, chalce- 
dony, carnelian, agate, jasper (in the débris of the lake shore), dog- 
tooth spar, augite, native silver, spodumene? chlorite ; near Pigeon 
Point, graphite, sphalerite, chalcopyrite, barite; between Pigeon 
Point ard Fond du Lac, near Baptism River, saponite (thalite) in 
amygdaloid ; between Split Rock R. and the Great Palisades, anor- 
thite rock ; in Mesabi Range, magnetite in beds. 

PrinE Co.—Kettle River Trap Range. Epidote, nail-head calcite, 
amethystine quartz, calcite, undetermined zeolites, saponite ; also 
copper ores. 

STILLWATER.—Blende. _ . 

FALLs or THE St. Crorx.—Malachite, native copper, epidote, nail- 
head spar (calcite). 

Rawwy Laxr.—d<Actinolite, tremolite, fibrous hornblende, garnet, 
pyrite, magnetite, steatite. 


WISCONSIN. 


Buivur Mounps.—Cerussite. 
Lac DE FLAMBEAU R.—Garnet, cyanite. 
Doveuas Co., Left-Hand R. (near small tributary).—Malachite, 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 387 


chalcocite, native copper, cuprite, malachite, niccolite, tetrahedrite, 
epidote, chlorite? quartz crystals. 

MINERAL Pornt and vicinity, in 8. W. counties of Wisconsin.— 
Copper and lead ores, chrysocolla, azurtte/ chalcopyrite, malachite, 
galenite, cerussite, anglesite, blende, pyrite, barite, calcite, marcasite, 
smithsonite / (including pseudomorphs after calcite and blende, so- 
called ‘‘dry-bone”’), calamine, bornite, hydrozincite; at Shullsburg, 
galenite/ blende, pyrite; at Emmet’s digging, galenite and pyrite. 

MonrreAu River PortaGe.—Galenite in gneissoid granite. 

Penokee and Menominee Iron Ranges S. of L. Superior, hematite, 
magnetite, siderite, actinolite, garnet. 

SAUK Co.—Hematite, malachite, chalcopyrite. 


IOWA. 


DusuquE LEAD Mines, and elsewhere.—Galenite/ calcite, blende, 
black oxide of manganese, barite, pyrite; at Ewing’s and Sherard’s 
diggings, smithsonite, calamine; at Des Moines, quartz crystals, sele- 
nite; Makoqueta R., limonite; near Durango, galenite; 7m.S. of Du- 
buque, aragonite. 

CEDAR ItvER, a branch of the Des Moines.—Selenite in crystals, in 
the bituminous shale of the Coal measures; also elsewhere on the 
Des Moines, gypsum abundant; argillaceous iron ore, siderite. 

Forr DopGE.— Celestite, gypsum, pyrite. 

New GALenA.—Octahedral galenite, anglesite. 

BENTONSPORT, and elsewhere in Southern Jowa, in geodes.—Chal- 
cedony, quartz, calcite, dolomite, pyrite, kaolinite. 


MISSOURI. 


For the distribution of the lead-mines see page 162. Mine la Motte, 
and some old openings in Madison Co., afford cobalt and nickel ores 
abundantly, At Granby and other mines the chief zinc ore is cala- 
mine, or the silicate of zinc, while in Central and Southwestern Mis- 
souri it is comparatively rare, and smithsonite is the prominent ore, 
as in Wisconsin; yet calamine is the most abundant zinc ore in the 
State. As stated by A. Schmidt, the zinc ore is a secondary product 
to sphalerite (blende); the cerussite often coats the galenite, or has 
its forms, indicating thus its source; the Jimonite is also secondary, 
and has come in mainly through the oxidation of pyrite. At the 
Granby mines the calamine is called, among the miners, *‘ Black 
Jack;” blende, ‘‘ Resin Jack;” a white massive smithsonite, ‘‘ White 
Jack;” and the cerussite is the ‘‘Dry Bone;” thus departing from 
ordinary miners’ usage. Gold has been found in the drift sands of 
Northern Missouri (Broadhead). 

ADAIR Co.—GOdthite in calcite. 

CoLE Co.—Old Circle Diggings and elsewhere, barite/ galenite, 
chalcopyrite, malachite, azurite, pyrite, calcite, calamine, sphalerite. 

CooPpER Co.—Collin’s mine, malachite, azurite, chalcopyrite, 
smithsonite, galenite, sphalerite, limonite. 

CRAWFORD Co.—At Scotia iron bed, hematite, amethyst, géthite, 
malachite. 

DavE Co,—Smithsonite. 


388 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


FRANKLIN Co.—Cove mines, Virginia mines, and mine 4 Burton, 
galenite, cerussite, anglesite, barite; at Staton copper-mine, native 
copper, chalcotrichite, malachite, azurite, chalcopyrite. 

Iron Co.—At Pilot Knob and Shepherd Mountain, hematite, mag- 
netite* limonite, manganese oxide, bog manganese, serpentine. 

JASPER Co. (adjoins 8. E. Kansas).—At Joplin mines and Oro- 
nogo, galena! sphalerite, pyrite, cerussite, calamine, dolomite, bitu- 
men. 

JEFFERSON Co.—Valle’s, galenite/ cerussite, anglesite, calamine, 
smithsonite, splalerite, hydrozincite, chalcopyrite, malachite, azurite, 
pyrite, dartte, witherite, limonite; Frumet mines, galenite, barite / 
smithsonite! pyrite, limonite. 

Maprison Co.—Mine la Motte, galenite! cerussite! stegenite (nickel- 
linneite), smaltite, asbolite (earthy black cobalt ore), bog manganese, 
chalcopyrite, malachite, caledonite, plumbogummite, wolframite. At 
Enistein silver-mine, galenite, sphalerite, wolframite, pyrite, quartz, 
muscovite, actinolite, fluorite. 

Morean Co.—Cordray Diggings, galena, blende, barite. 

Newton Co. (adjoins S. E. Kansas).—Granby mines, galenite/ 
cerussite, calamine! sphalerite, smithsonite, hydrozincite, buratite, 
greenockite (on sphalerite), pyromorphite, dolomite, calcite, bitumen. 

St. Frangors Co.—Iron Mountain, hematite, limonite, apatite, 
tungstite, wolframite, magnetite, menaccanite. 

Sr. GENEVIEVE Co.—At copper-mines, chalcopyrite, cuprite, mala- 
chite, azurite, covellite, chalcocite, bornite, melaconite, chalcanthite. 

St. Louis Co.—Near St. Louis, mzllerite (in the Subearboniferous 
St. Louis limestone, largely a magnesian limestone) with calcite / 
barite, flworite, anhydrite, gypsum, strontianite, 

WASHINGTON Co.—At Potosi, galenite, cerussite, auglesite, barite. 


ARKANSAS. 


BATESVILLE.—In bed of White R., above Batesville, gold. 

GREEN Co.—Near Gainesville, lignite. . 

Hot Sprines Co.—At Hot Springs, waveliite, thuringite, novacu- 
lite; Magnet Cove, brookite! schorlomite, eleolite, magnetite, quartz, 
green coccolite, garnet, apatite, perofskite (hydrotitanite), rutile / 
ripidolite, thomsonite (ozarkite), microcline, egirite, protovermiculite, 
variscite. 

LAWRENCE Co.—Smithsontte, dolomite, galenite; nitre. 

Marion Co.—Wood’s mine, smithsonite, hydrozincite (marionite) 
galenite; Poke bayou, braunite? 

MontTaoMERY Co.—Variscite. 

PuLaski Co.—Kellogg mine, 10 m. north of Little Rock, tetrahe- 
drite, tennantite, nacrite, galenite, blende, quartz. 

SEVIER Co.—Stibnite, stibiconite, bindheimite, jamesonite. 


KANSAS. 


Brown Co.—Celestite. 

Linn Co., and elsewhere, near Missouri line.-—Lead and zinc ores; 
on Short Creek, galenite, cerussite, anglesite, sphalertte, calamine, 

WALLACE Co., etc.—Gypsum in crystals. #! 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 389 


DAKOTA. 


LAWRENCE Co.—Redwater Valley, gypsum, Bear Lodge range, 
gold. 

PENNINGTON Co.—Etta mine, spodumene ! cassiterite, mica, ortho- 
clase, columbite/ leucopyrite, scorodite, olivenite. The Ingersoll 
claim, 10 m. E. of Harney Peak, columbite, tantalite, beryl; Bald 
Min., pitchblende, torbernite or autunite. . 


MONTANA. 


Mountains in which mines occur cover the southwestern part and 
the western. Commencing on the west: 

SILVER Bow Co. (formerly southern part of Deer Lodge Co.).— 
Summit Valley district, in veins in granite or related rocks (near 
Butte City), cerargyrite, argentite, chalcocite, galenite, silver, gold, mala- 
chite, chalcopyrite, bornite, pyrite, cerussite, freibergite, sphalerite, 
manganese ores; Independence distr. and Flint Creek distr. (near 
Phillipsburg), similar ores with hiibnerite. 

BEAVER HEAD Co. (S. of Silver Bow Co.)—Near Bannack City, 
gold and tellurium with pyrite, some galenite, nagyagite; in Bald 
Mtn. and Trapper districts, ores of lead and copper with silver in 
limestone. 

Lewis & CLARKE Co.—Silver Creck, in veins in slates and slaty 
limestones, gold, with some ores of lead and copper and a little sil- 
ver; at Helena, gold-bearing veins. 

JEFFERSON Co.—Gold, aurif. pyrite, some galenite and silver. 

Mapison Co.—Silver Star distr., gold in veins in gneiss, some 
copper and silver ores, manganese ores; Mineral Hill distr. and N. 
of Virginia City, in gneiss, argentif. galenite, gold; similar ores and 
rock in Hot Springs and Red Bluff districts. 


WYOMING. 


ALBANY Co., 14 m. 8. W. of Laramie City.—Thenardite. 

LARAMIE Co.—Near Hartville, chalcocite, chrysocolla, cuprite, 
malachite; 18 m. E. of Laramie City, graphite. 

SWEETWATER Co.—Near Atlantic City, 8. Pass City, and Miner’s 
Delight, gold in quartz veins; near Independence Rock, sodium car- 
bonates (trona, etc.). 


IDAHO. 


ALTURAS Co. (veins mostly in granite).—Middle Boisé, rudy silver, 
native silver, gold, cerargyrite, stephanite, argent, galenite, argentite, py- 
vite, chalcopyrite, freibergite, arsenopyrite, sphalerite; Hardscrabble, 
gold, pyrite, arsenopyrite. Other mines at Bonaparte (gold and silver 
ores), Mineral Hill (silver ores), Queen’s River (gold and silver ores), 
Red Warrior (gold and silver ores), Rocky Bar (gold), Sawtooth 
(silver ores); at Jay Gould mine, with the other ores, native lead. 

Boisé Co. (veins in granite).—Banner, ruby silver ore, cerargyrite, 
pyrite; gold at Cafion Creek, Gambrinus, Granite, Shaw’s Mountain, 
etc. 


390 SUPPLEMENT TO DESCRIPTIONS OF SPECIES, 


Ipano Co.—Warren’s Camp (veins in slate and limestone), gold, 
silver, cerargyrite, etc., scheelite with gold (Charity mine). 

Lemur Co.—Bay Horse (veins in slate), argent. galenite, chalcocite, 
cerargyrite, bromyrite, malachite, gold; Yankee Fork, gold, pyrite, 
chalcopyrite, stephanite? 

OwnyYnEE Co.—(Veins in granite, metamorphic, and other rocks 
intersected by dikes of igneous rocks, situated near Silver City, on 
the Jordan R.) Carson, gold, silver, cerargyrite, etc.; Wagontown, 
gold, argentite, pyrite, stephanite; on Jordan R., stream tin. Gold 
also in Oneida Co., at Cariboo and Iowa Bar, Kootenai, Nez Percé, 
Shoshone and Washington Cos.; Bear Lake Co. (8S. E. corner of 
Idaho), near Soda Spring, soda carbonate, salt, sulphur. 





COLORADO. 


BovunpDER Co. (eastern part, between Jamestown and Magnolia, 
noted for rich tellurides with tellurium).—Central distr. (Smuggler 
mine, etc., in mica schist or gneiss); tellurides, pyrite; Gold Hill distr. 
(Red Cloud, etc., mines), gold, tellurides of gold, silver, mercury, 
pyrite, sphalerite, chalcopyrite; Magnolia distr., tellurides, etc., tel- 
‘ Jurium ores of the range including altaite, hessite, petzite, sylvanite, 
tellurite, native tellurium, calaverite, coloradoite, melonite, ferro-tellurite, 
magnolite, and the associated ores, argentijte, amalgam, native mer- 
cury, native bismuth, bismuthinite, bismutite, pyrargyrite, iodyrite, 
kobellite, schirmerite, hiibnerite; Sunshine and Sugar Loaf districts 
afford tellurides; Ward distr., aurif. pyrite and chalcopyrite, gold; 
Grand Island distr. (Caribou mine), argentif. galenite, chalcopyrite, 
pyrite, gold, sphalerite; Sugar-Loaf distr., chalcocite, pyrrhotite, 
manganesian garnet. 

CHAFFEE Co.—Arrow mine, jarosite with turgite; gold gravels (at 
Cash Creek, etc.); Monarch distr., cerussite, brochantite, etc.; near 
Mt. Anteros, in Arkansas Valley, beryls; at Salida, garnets; at 
Nathrop, in cavities in rhyolyte, topaz, garnet. 

CLEAR CREEK Co.—Georgetown, argentif. galenite, native silver’, 
pyrargyrite, argentite, tetrahedrite, pyromorphite, sphalerite, azurite, 
aragonite, barite, fluorite, polybasite (Terrible Lode), mica; Trail 
Creek, garnet, epidote; Freeland Lode, tetrahedrite, tennantite, 
anglesite, caledonite, cerussite, tenorite, siderite, azurite, minium; 
Champion Lode, tenorite, azurite, chrysocolla, malachite ; Gold Belt 
Lode, vivianite; Coyote Lode, malachite, cyanotrichite; Virginia 
district, galenite, chalcopyrite, pyrite, tetrahedrite. 

Custer Co.—Near Rosita and Silver Cliff, 6m. W. of R., argent. 
galenite, sphalerite, pyrite, chalcopyrite, annabergite, carrying silver 
and gold, ores at the latter place incrusting fragments or pebbles. of 
country rock, calamine, smithsonite, jamesonite, tetrahedrite, tellurites 
of silver and gold, niccolite ; also at the Racine Boy mine, cerussite, 
cerargyrite; at the Gem mine, 12 m.N. of Silver Cliff, niccolite, 
bornite, pyrite; E. slope of Sangre de Cristo, Verde mine, chalcopyr- 
ite, tetrahedrite, pyrite. 

Ex Paso Co. (includes, in W. part, Pike’s Peak).—25 m. N. of 
Pike’s Peak, near Platte (Devil’s Head) Mtn., topaz / microcline, albite, 
phenacite, smoky quartz, gothite, fluorite, cassiterite, allanite, gadolin- 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 391 


ite; near Florissant, 12m. N. W. from the Peak, microciline / topaz / 
on Elk Creek, phenacite, microcline (amazon stone), smoky quartz! 
amethyst ! albite, fluorite, zircon! columbite/ ; south of Manitou, in 
Crystal Park, topaz, phenacite, zircon. Near Pike’s Peak toll-road, 
W. of Cheyenne, N. E. base of St. Peter’s Dome, in quartz vein, 
gircon, astrophyllite, arfvedsonite, cryolite, thomsenolite, gearksutite, 
prosopite, ralstonite, elpasolite, tysonite, bastneesite; in another vein, 
prosopite, zircon, fluorite, kaolinite, yellowish mica, cryolite; between 
Colorado Springs and Cajfion City, barite; Garden of the Gods, cel- 
estite, rhodochrosite. 

GitPpIn Co.—Veins in gneiss or granite. Near Central City, 
Gregory dist., about Black Hawk (Bobtail mine, etc.), chalcopyrite, 
pyrite, sphalerite, galenite, enargite and fluorite; in Willis Gulch, 
uraninite (Wood mine); Nevada district (next west of Gilpin), galen- 
ite, chalcopyrite, pyrite, sphalerite, etc.; Russell dist. (in Russell 
Gulch), galenite, tetrahedrite, enargite, pyrite, fluorite, chalcopyrite, 
pyrite, epidote. 

GuNNISON Co. (W. of Sawatch Mis. and S. of Elk Mts.).—Ruby 
district, ruby silver, arsenopyrite, in quartz vein; on Brush Creek, 
W. base of ‘Teocalli Mtn., nickeliferous (dllingite, smaltite, marcasite, 
native silver, proustite, pyrargyrite, argentite, galenite, chalcopyrite, 
in a gangue of siderite, barite, and calcite. 

HINSDALE Co.—Lake City, Hotchkiss Lode, petztte, calaverite; Lake 
district, argent. galenite, freibergite, sphalerite, aurif. chalcopyrite, 
argentobismutite; Park district, stephaniie, galenite, chalcopyrite; 
Galena district, argent. galenite, freibergite, sphalerite, chalcopyrite, 
rhodocrosite, stephanite, ruby silver, gold, silver. 

HvuERFANO Co.—Southern border, N. slope, W. Spanish Peaks, 
galenite, pyrite, chalcopyrite, tetraledrite, 

JEFFERSON Co.—Near Golden, on Table Mtn., leucite, analette, apo- 
phyllite, chabazite, levynite, laumontite, mesolite, natrolite, scolecite, 
stilbite, thomsonite, calcite, aragonite; Turkey Creek, columbite. 

Lake Co. (between Mosquito Mts. and Sawach Range, both 
Archean at centre), supplying three fourths of the silver and gold of 
Colorado, with Paleozoic rocks between, and great eruptive forma- 
tions.—About Leadville (or California mining district), on W. portion 
of Mosquito Range, and mostly confined to Lower Carbonif. limestone, 
and generally beneath eruptive rocks, sélver, galenite, cerussite, angle- 
sile, cerargyrite, bromyrite, iodyrite, embolite, aurif. chalcopyrite and 
pyrite, sphalerite, pyromorphite, minium, pyrolusite, rhodochrosite, cala- 
mine, sphalerite, bismuthinite, bismutite, gold, dechenite (in Morning 
Star and Evening Star mines), kobellite (Printer Boy hill); Florence 
mine, bismutite; Uteand Ule mines, stephanite, galenite, sphalerite, chal- 
cocile ; Homestake Peak, N. W. corner of county, argent. galenite ; 
Golden Queen mine, scheelite, gold. 

La Puata Co. (S. of San Juan Co,).—S. side of La Plata Mts., 24 
m. N. of Parrott City, aurif. pyrite, galenite, tetrahedrite, cosalite 
(Comstock mine). 

Ouray Co. (W. of N. end of Hinsdale Co., with Uncompaghgré 
Mts. between).—Near Ouray, argent. galenite, some freibergite, chal- 
copyrite, pyrite, hibnerite, rhodochrosite; at National Bell mine, kao- 
linite in cryst. 


392 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


Park Co.—Mines chiefly along its northwest side, on the E. slope 
of the Mosquito range, in the Paleozoic region of its eastern side, near 
eruptive rocks. In N. part Hall’s Valley, veins in gneiss, galenite, 
tetrahedrite, enargite, pyrite, sphalerite, fluorite, barite, ilesite; near 
Grant, Baltic Lode, begeerite, N. W. of Alma, on Mts. Bross and Mt. 
Lincoln, in Carbouif. limestone, argent. galenite, cerussite, anglesite, 
cerargyrite, barite, Manganese oxide; in Buckskin Gulch (between 
these mts.), in Cambrian quartzyte, aurif, pyrites, gold, silver, galenite; 
Sweet Home and Tanner Boy mines, 8. W. side of Mt. Bross, in 
Archean, vhodochrosite in the latter; in Mosquito Gulch, south of | 
Alma, near Horseshoe, argent. galenite, cerussite. Mines of Lincoln 
Mtn. at 13,000 to 14,000 ft. elevation. 

Pirkin Co. (between Elk Mts. and Sawatch Range).—At Indepen- 
dence, on W. slope of Sawatch, on the Roaring Fork, in Archean, and 
west of Aspen, on the N. E. slope of Elk Mts., Alpine Pass, Pitkin 
and Tin Cup mines, in limestone, cerussite, cerargyrite, cuprite. 

Rio GRANDE Co.—At head of Rio Alamosa, near Summitville, E. 
part of San Juan Mts., gold, in quartz veins, enargite. 

San JUAN Co. (S. and 8. E. of E. end of San Miguel Co., crossed 
by the San Juan Mts.).—Animas and Eureka districts, about Baker’s 
Park and Silverton, freibergite, argent. galenite, cerussite, azurite, 
malachite, chalcopyrite, chalcocite, covellite, barite, zunyite, and 
guitermamite (at Zui mine); Red Mtn. dist. (Brobdignag mine), 
einkenite, enargite, tennantite, hiibnerite (Adams’ mine); Poughkeep- 
sie Gulch, Alaska mine, alaskaite, chalcopyrite, tetrahedrite, barite, 
tellurite; Yankee Girl mine, cosalite. 

San MicueEu Co. (8S. of Ouray Co., eastern part including N. por- 
tion of San Juan Mts.).—At Sneffels (near Mt. Sneffels), freibergite, 
stephanite, argent. galenite, cerussite, etc.; Upper San Miguel and 
Iron Springs districts, similar ores; at Telluride, galena, stephanite, 
chalcopyrite, gold, electrum. 

Summit Co.—In southeastern part, on W. slope of Archzan 
‘‘Front Range,” near Montezuma and Peru, argent. galenite, etc. ; 
in southern part, near headwater of Blue R., 8. of Breckenridge, near 
Robinson, on Quandary Peak, etc., in limestone, argent. galenite, 
pyrite, native gold, sphalerite; Chalk Mtn., junction of Summit Park 
and Eagle Cos., in rhyolyte (nevadite), sanzdin, topaz in small crys- 
tals; Snake River district, alabandite (Queen of the West mine), with 
rhodocrosite. 


UTAH. 


The silver-mines are mostly in limestone, with eruptive rocks in 
the vicinity, and argentif. galenite, cerussite, anglesite, cerargyrite, 
ete., the common ores. The veins in slate or quartzyte in part 
carry copper ores. There are also, as shown first by Prof. Newberry, 
sandstones in Southern Utah impregnated by ores (cerargyrite, etc.) 
over large regions. 

BEAVER Co.—Bradshaw, cerussite, cuprite, malachite, aragonite; 
San Francisco, cerussite, anglesite, galenite, dufrenoysite, proustite, 
pyrargyrite, cerargyrite, argentite, barite; Star, cerussite, cerargyrite, 
malachite. 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 393 


Iron Co.—Coyote district, orpiment, realgar, thin layer in strata 
under lava. 

JUAB Co.—Tintic district, galenile, anglesite, cerussite, malachite, 
bornite, cuprite, bismuthite, olivenite, conichalcite, chenevixite, jarosite, 
calcium arsenate (at American Eagle mine); enargite (at Mammoth, 
Shoebridge, and Dragon mines); 40 m. N. of Sevier Lake and 
ie m.W. N. W. of Deseret, topaz in rhyolyte, with garnet and sani- 

in. 

PiruTE Co.—Ohio, galenite, cerussite, malachite, chalcopyrite, chal- 
cocite, tetrahedrite; Mt. Baldy, galenite, cerussite, anglesite, wulfenite, 
argentite (Pluto mine); Marysvale, onofrite. Tiemannite (at Lucky 
Boy mine). 

SaLT Laker Co.—Big Cottonwood, galenite, cerussite, anglesite, mala- 
chite, with sometimes pyrolusite; Little Cottonwood, at Emma and 
other mines, same, with sometimes argentite, dufrenoysile, wu/fentte, 
linarite, chalcopyrite, enargite (at Oxford and Geneva mine); West 
Mountain, same ores, with argentite, pyrargyrite, rhodochrosite, 
barite at Queen mine; binnite, etc., at Tiewaukee mine; dufrenoy- 
site, etc., at Winnamuck mine; Butterfield Cafion, orpiment, realgar, 
mallardite, luckite; Wasatch Mts., head-waters of Spanish Fork, 
ozocerite in beds. 

Summit Co.—Uintah, cerussite, anglesite, cerargyrite, tetrahedrite, 
argentite, malachite. 

'TooELE Co.—Camp Floyd, stibnite, etc.; Ophir, galenite, cerussite, 
malachite, chalcopyrite, cerargyrtie, Rush Valley, same ores: American 
Fork and Silver Lake, same ores. 

Wasatcu Co.—Blue Ledge and Snake Creek, galenite, cerussite, 
pyromorphite, sphalerite, etc. 

WASHINGTON Co.—Harrisburg, in sandstone and clay, native silver, 
cerargyrite, argentite; fossil plants sometimes replaced by silver and 
cerargyrite, 


NEW MEXICO. 


DoXa ANA Co.—At Lake Valley, in the Sierra mines, in limestone, 
argent. galenite, cerussite, cerargyrite, embolite, iodyrite, manganese 
ores, vanadinite, endlichite, descloizite, native silver, pyrolusite, man- 
ganite, fluorite, apatite; Victoria mine, 40 m. below Nutt, anglesite; 
at Kingston, in Black Range, aragonite. 

Grant Co.—8. W. corner of N. Mexico, adjoining Arizona.—In N. 
E. corner of county, 8. part of Mimbres Mtn., E. of Silver City, ores 
in limestone or shale, argentif. galenite, cerargyrite, argentite, native 
silver, barite, fluorite; Santa Rita mines, in porphyry near limestone, 
native copper, tenorite; Pinos Altos Mtn., N. of Silver City, argent. 
galenite. cerargyrite, cerussite, argentite, silver, gold, chalcopyrite, 
barite; Burro Mts., 8. W. of Silver City, similar ores; in 8. W. part 
of Co., near Barney’s Station and Warren, Virginia distr., veins of 
quartz, with argent. galenite, cerargyrite, native silver. 

Santa F'& Co.—LosCerillos dist., 22 m. S. W. of Santa Fé, in L. 
C. Mts., turquois in trachyte, argent. galenite, cerussite, wulfenite, 
manganese ores; Silver Bute distr., in quartzyte, gold, pyrite, azurile, 
malachite, cuprite, chalcopyrite, bournonite, chrysocolla, 


394 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


Srerra Co. (S. of Socorro Co.).—Near Hillsboro’, gold in veins 
and placers. 

Socorro Co, (N. E. of Grant).—3 m. from Socorro, in Socorro 
Mis., cerargyrite, vanadinite, vanadiferous mimetite, barite; in Magda- 
lena Mts., 27 m. W. of Socorro, galenite, cerussite, anglesite, cala- 
mine, sphalerite; Oscuro Mts. to E., chalcopyrite, azurite, malachite, 
associated with fossil wood and plants; at Grafton, gold, cerussite, 
chalcocite, bornite, malachite, chalcopyrite, cerargyrite, amethyst. 


ARIZONA. 


ApacHEe Co.—Copper Mountain, chalcocite, azurite, melaconite, 
sphalerite, pyrite; and at Greenlee Gold Mountain, chalcocite, mala- 
chite, cuprite, auriferous gravel. ¥ 

CocuisE Co. (S. E. corner of State).—20 m. from Tombstone, 
turquois (chalchuite); Bisbee, malachite, aurichalcite. 

GranHam Co.—Clifton, dioptase, cuprite, azurdle, chrysocolla. 

Maricopa Co.—Vulture district (and on borders of Yavapai Co.), 
at Farley’s Collateral mines (20 m. N. of V.), vanadinite, chrysocolla, 
crocoite, descloizite, gold; at Phenix and other mines near the last, 
vanadinite, gold, vauquelinite, crocoite, phoenicochroite, silver, sphaler- 
ite, argentite, pyrargyrite; Tip Top (at Humbug, in Yavapai Co.), 
east of last, stlver, sphalerite, argentite, pyrargyrite; 24 m. 8S. W. of 
Fort Verde, large bed of thenardite; Globe district (partly in Pinal 
Co.), argentite, stromeyerite, bornite, chalcopyrite, chalcocite, mala- 
chite, cuprite, manganese ore, barite; Jerome, gerhardtite. : 

MounaAveE Co. (veins in granitoid rocks).—Hualapai district, galenite, 
cerussite, sphalerite, ruby silvers, chalcopyrite, pyrite; Maynard, gale- 
nite, stephanite, argentite, silver, gold, cerargyrite, sphalerite; Cedar 
Valley district (Congress and other mines), galenzle, ruby silvers, tet- 
rahedrite, cerargyrite, sphalerite, pyrite; Owens district (Signal mine, 
etc.), galenite, argentite, etc. 

Pima Co.—Many of the veins in limestone, which is probably Car- 
boniferous, near eruptive rocks, and others in granite; Oro Blanco, 
near Mexican line, argentif. galentte, cerussite, malachite, cerargyrite, 
freibergite, etc.; Arivaca, Tubac, similar ores; Tombstone, galenite, 
cerargyrite, silver, gold, cerussile, malachite, pyrolusite; similar ores at 
Hartford, Meyers, etc.; near Tucson, copper ores; Turquois (western 
part of county, Ajo mine in quartzyte), chalcopyrite, bornite, mala- 
chite; and Defiance mine in limestone, argent. galenite, cerussite. 

Pinau Co.—Globe (Stonewall Jackson, etc., mines). See MARI- 
copa Co.—Pioneer (Silver King, El Capitan, and other mines), szlver, 
Jreibergite, argentite, stephaniite, stromeyerite, chalcopyrite, bornite, 
malachite, azurite, galena, sphalerite, pyrite, polybasite, miargyrite, 
pyrargyrite (last three from El Capitan); vanadinite and wulfenite 
(Black Prince mine, Pioneer distr.). 

Yavapat Co.—Big Bug (Silver Belt mine, in gneiss or granite), 
galentte, cerussite, cerargyrile, barite, calcite; Jerome, gerhardtite. See 
further, Maricopa Co. 

Yuma Co.—Castle Dome, in gneiss, argent. galenite, anglesite, ce- 
gussite, fluorite, vanadinite, wulfenite, mimetite; Silver district (veins 
in gneiss and mica slate, Hamburg, Princess, Red Cloud, etc., mines), 
argent. galenite, anglesite, cerussite, wulfenite, vanadinite, fluorite. 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 395 


NEVADA. 


The chief mining regions of Nevada affording silver and partly 
gold are either veins connected obviously with igneous eruptions, as 
the Comstock Lode; veins in granitic or metamorphic rocks, as 
the Austin mines; and deposits or supposed veins in limestone, either 
of the Cambrian or later age, as the Eureka and White Pine mines. 

Cuuncuint Co.—Ragtown, gay-lussite, trona, halite; Cottonwood 
Campus, niccolite, annabergite. 

Evxo Co.—Tuscarora, veins in igneous rocks, stephanite, cerargy- 
rite, ruby-silver ores (proustite and pyrargyrite), argentite, stephanite, 
chalcopyrite, pyrite, sphalerite, chrysocolla. 

EsMERALDA Co.—In metamorphic slates and schists, or in granite, 
which are intersected by igneous rocks, at Columbus, gold, cerargy- 
rile, tetrahedrite, galenite, pyrite, sphalerite, pyrolusite, turquois, 
stetefeldite; also gold in Esmeralda and Wilson in quartz; silver, ga- 
lenite, and chalcopyrite in Oneota, in mica schist; Alum, 12 m. N. of 
Silver Creek; at Aurora, fluorite, stibnite; near Mono Lake, native 
copper and cuprite, obsidian; Thiel Salt Marsh, wleaxite, borax, com- 
mcn salt, thenardite ; Columbus district, ulexite, thenardite, sulphur; 
Walker Lake, gypsum, hematite. 

Evurexa Co.—Eureka, Ruby Hill, etc., in Lower Cambrian lime- 
stone, gold, silver, cerussite, galenite, anglesite, mimetite, wulfenite, 
limonite, aragonite; at Cortez, cerargyrite, tetrahedrite, silver, etc. 

Humpotpt Co.—Veins in Mesozoic slates, at Paradise; sever, ce- 
rargyrile, tetrahedrite, pyrargyrite, proustite, stephanite, arsenopyrite, 
chalcopyrite, sphalerite, pyrite; between slate and granite at Winne- 
mucca, sulphides and antimonial sulphides of lead, with silver, jame- 
sonite, stibnite, bournonite; near Lovelock’s Station, erythrite, mil- 
lerite, asbolite. 

LANDER Co.—At Austin, near Reese River, in the Toyabe Range, 
which bas a granitic axis flanked by Paleozoic strata, and the veins 
in the granite of Lander Hill (yielding $1,000,000 of silver annually), 
situated near the western edge of the Paleozoic area of the eastern 
half of the Great Basin, tetrahedrite, pyrargyrite, proustite, cerargyrite, 
stephanite, polybasite, rhodochrosite, embolite, chalcopyrite, pyrite, 
galenite, azurite, whitneyite; also mines at Lewis of ruby silver, 
etc., in quartzyte; and at Battle Mountain, of galenite in Paleozoic 
slate. 

Lincoun Co.—Bristol, galenite, cerussite, etc.; Eidorado, cerargy- 
rite, stromeyerite; Jack-Rabbit, argentif. galenite, cerussite, cuprite, 
malachite; Ely, gold, cerargyrite, galenite, sphalerite, pyrite. 

Nye Co.—At Belmont (vein in Silurian slate), argent. galenite, 
stephanite, pyrite, chalcopyrite, anglestte, stetefeldite ; Morey, ruby 
silver and other arsenical and antimonial ores, etc.; Tybo, galenite, 
cerargyrite, etc.; Union, cerargyrite, galenite, sphalerite, etc.; Dow- 
nieville, anglesite, cerussite, wulfenite, sphalerite, pyrite. 

Storey and Lyon Cos.—Mines of the Comstock Lode, gold, native 
silver, argentite, stephanite, polybasite, ruby-silver ores, tetraledrite, 
cerussite, wulfenite, kiistelite, ete. 

Wurtt Prinz Co.— White Pine, in Devonian limestone, cerargyrite; 
at Ward, same limestone, sulphantimonides (probably stromeyerite), 
pyrite, etc. ; at Cherry Creek, copper carbonate, sulphides, etc. 


396 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


CALIFORNIA. 


The principal gold regions are in Fresno, Mariposa, Tuolumne, 
Calaveras, El Dorado, Placer, Nevada, Yuba, Sierra, Butte, Plumas, 
Shasta, Siskiyou, and Del Norte counties, although gold is found in 
almost every county of the State. 

The copper-mines are principally at or near Copperopolis, in Cala- 
veras County; near Genesee Valley, in Plumas County; near Low 
Divide, in Del Norte County; on the north fork of Smith’s River; 
at Soledad, in Los Angeles County. 

The mercury-mines are at or near New Almaden and North Al- 
maden, in Santa Clara County; at New Idria and San Carlos, Mon- 
terey County; in San Luis Obispo County; at Pioneer mine, and 
other localities in Lake County; in Santa Barbara County. 

ALAMEDA Co.—Diabolo Range, magnesite. 

ALPINE Co.—Morning Star mine, enargite, stephanite, polybasite, 
barite, quartz, pyrite, tetrahedrite, pyrargyrite. 

Amavor Co.—At Volcano, chalcedony, hyalite; Ione Valley, 
chalcopyrite, ionite, lignite; Fiddletown, diamond; gold at several 
mines with chalcopyrite, pyrite, galenite. 

BERNARDINO Co.—At Borax works, hanksite/ 

Burre Co.—Cherokee Flat, diamond, platinum, iridosmine, 
chromite, zircon. 

CALAVERAS Co.—Copperopolis, and Campo Seco, chalcopyrite, 
malachite, azurite, serpentine, picrolite, native copper; near Murphy’s, 
jasper, opal; albite, with gold and pyrite; Mellones mine, calaverite, 
petzite. 

CoLusE Co.—Butte City, Gagnon mines, goslarite, wurtzite. 

Det Norte Co.—Crescent City, agate, carnelian; Low Divide, 
chalcopyrite, bornite, malachite; on the coast, iridosmine, platinum, 
gold in gravel, zircon, diamond. 

Et Dorapvo Co.—Pilot Hill, chalcopyrite; near Georgetown, hes- 
site, from placer diggings; Roger’s Claim, Hope Valley, grossular 
garnet, in copper ore; Coloma, chromite ; Placerville, gold ; Granite 
Creek, roscoeclite, gold; Forest Hill, diamond; Cosumnes mine, 
molybdenite. 

FrRrEsNo Co.—Chowchillas, andalusite ; King’s River, bornite; 
New Idria, cinnabar. 

HumBoipt Co.—Cryptomorphite. 

Inyo Co.—Inyo district, galenite, cerussite, anglesite, barite, ataca- 
mite, calcite, grossular garnet / vesuvianite, datolite; Panamint, 
tetrahedrite, stromeyerite; Kearsarge mine, cerussite, tetrahedrite, 
cerargyrite, argentite; Cerro Gordo, wulfenite, cerussite, anglesite, 
polvbasite. 

KrrN Co.—Green Monster mine, cuproscheelite. 

Lakit Co.—Borax Lake, boraz/ sassolite, glauberite ; Pioneer 
miue, Cinnabar, native mercury, selenide of mercury; near the Gey- 
sers, sulphur, hyalite, cinnabar; Lower Lake, chromite. 

Los ANGELES Co.—Near Santa Anna River, anhydrite ; Williams 
Pass, chalcedony; Soledad mines, chalcopyrite, garnet, gypsum; 
Mountain Meadows, garnet, in copper ore; at Brea Branch, vivianite 
nodules with asphaltum; at Compton, Kelsey mine, erythrite. 

Mariposa Co.—Chalcopyrite, itacolumyte; Centreville, cinnabar; 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 397 


Pine Tree mine, tetrahedrite; Burns Creek, limonite; Geyer Gulch, 

pyrophyllite; La Victoria mine, azuritte / near Coulterville, cinnabar, 
old. 

: Mono Co.—At Blind Spring, Partzite (stibiconite), chalcocite, 
chalcopyrite, tetrahedrite; at Bodie, gold, silver; at Iridian, tetra- 
hedrite, sphalerite, galenite, silver. 

Monterey Co.—Alisal mine, arsenic; near Paneches, chaleedony; 
New Idria mine, cénnabar ; near New Idria, chromite, zaratite, 
chrome garnet; near Pacheco’s Pass, stibnite. 

Napa Co.—Chromite; at Cat Hill, Redington mine, cinnabar, 
metacinnabarite, marcasite, bitumen. 

Nrvapa Co.—Grass Valley, gold/ in quartz veins, with pyrite, 
chalcopyrite, blende, arsenopyrite, galenite, guvartz, biotite; near 
Truckee Pass, gypsum; Excelsior Mine, molybdenite, with gold; 
Sweet Land, pyrolusite. 

PLACER Co.—Miner’s Ravine, epidote/ with quartz, gold. 

Puumas Co.—At Cherokee, chalcopyrite. 

SanTA BARBARA Co.—San Amedio Cafion, stibnite, asphaltum, 
bitumen, maltha, petroleum, cinnabar, iodide of mercury; Santa 
Clara River, sulphur. 

San BERNARDINO Co.—Colorado River, agate, trona; at Clarke 
and Silver Mountain, stromeyerite, malachite; at Temescal Mts., 
cassiterite; Russ District, galenite, cerussite; Francis mine, cerar- 
gyrite; Slate Range, thenardite, borax, common salt, hanksite; San 
Bernardino Mts., graphite, 

SanTA CLARA Co.—New Almaden, einnabar, mercury, calcite, 
aragonite, serpentine, chrysolite, quartz, aragotite; North Almaden, 
chromite; Mt. Diabolo Range, magnesite, datolite, with vesuvianite 
and garnet. 

San Francrsco Co.—Red Island, pyrolusite and manganese ores. 

San Luis Opispo Co.—Asphaltum, cinnabar, native mercury, 
chromite. 

SrERRA Co.—Forest City, gold, arsenopyrite, tellurides. 

Sonoma Co.—At Guerneville, actinolite, garnets, chromite, ser- 
pentine, cinnabar, bitumen. 

Trinity Co.—At Cinnabar, cinnabar, serpentine, 

TUOLUMNE Co.—Tourmaline, tremolite; Sonora, graphite, gold, 
chalcopyrite, pyrite; York Tent, chromite; Golden Rule mine, 
petzite, calaverite, altaite, hessite, magnesite, tetrahedrite, gold; 
Whiskey Hill, gold / 


LOWER CALIFORNIA. 
LA Paz, cuproscheelite. Lorerro, natrolite, siderite, selenite. 
VOLCANO OF CERRO DE LAS VIRGINES, leucite. 


OREGON. 


Gold is obtained west of the Cascade Range, in the southernmost 
counties, Josephine, Jackson, and Curry, in Coos and Douglass, 
the next north, and east of the range, in southeastern Oregon, in 
Grant and Baker counties, and to the north sparingly in Wasco, 


398 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


Umatilla, and Union counties. The most productive mines are in 
Baker Co. 

LBaKER Co.—In northern part, about Baker City, Rye Valley, 
Bridgeport on Burnt River, Willow Creek, Silver Creek, gold; Rye 
Valley and Silver Creek affording also stromeyerite, arsenopyrite, 
pyrite, malachite, azurite. 

Curry Co.—Near Port Orford and Cape Blanco, and on the 
Rogue River, gold, platinum, iridosmine, laurite. On the seashore, 
5m. N. of Chetko, priceite, in veins and in masses from 20 lbs. 
weight to the size of peas and smaller, with bluish steatite. 

DoveLass Co.—New Idrian, cinnabar, limonite; in Piney Mtn., 
hydrous nickel silicate. 

Grant Co.—Granite, in north part of county, tetrahedrite, poly- 
basite, chalcopyrite, pyrite, sphalerite. At Elk Creek, auriferous 
gravel; near Canyon City (on John Day’s R.) cinnabar. 

JACKSON Co.—At Applegate and elsewhere, auriferous gravel. 

JOSEPHINE Co.—Auriferous gravel; at Yank, galenite, chalcopy- 
yitesi 
Wasco Co.—At Ochoco, auriferous gravel. 


WASHINGTON. 


Kine Co.—Seattle, scheelite, tourmaline; magnetite at Iron 
Mt., 3m. N. W. of Snoqualmie Pass, and also copper ores at the 
Denny Co. mine. 

Srevens Co.—Colville district mines of lead and silver reported. 

Wuatcom Co.—Fidalgo, tourmaline. 

Yakima Co.—Auriferous gravel and quartz veins. 


DOMINION OF CANADA. 
PROVINCE OF QUEBEC. 


ABERCROMBIE.—Labradorite. 

ALDFIELD, Pontiac Co.—Molybdenite ! / 

ALLEYN ‘lowNsHIP, Pontiac Co.—Molybdenite, mnlyhaee 

AUBERT.—Gold, iridosmine, platinum. 

Batre Sr. PAuL.—Menaccanite / apatite, allanite, rutile. 

Bo.ron.— Chromite, magnesite, serpentine, picrolite, steatite, bitter 
spar, wad, rutile. 

BoucuHERVILLE.—Augite in trap. 

BRASSARD, Berthier Co.—Samarskite. 

Brome.—Magnetite, chalcopyrite, sphene, menaccanite, phyllite, 
sodalite, cancrinite, galenite, chloritoid, rutile. 

Broveuron. —Serpentine, chrysotile, 'steatite. 

BucKkINGHAM TownsHIP, Ottawa County.—Apatite and various 
associated minerals. 

CHAMBLY.—Analcite, chabazite and calcite in trachyte, menac- 
canite, 

CHATEAU RicuER.—Labradorite, hypersthene, andesite. 

DaILLEBOUT.—Blue spinel with clintonite. 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 399 


GRENVILLE.—Wollastonite, sphene, muscovite, vesuvianite, cal- 
cite, pyroxene, serpentine, steatite (rensselaerile), chondrodite, garnet 
(cinnamon-stone), zircon, graphite, scapolite. 

Firzroy.—Graphite. 

Ham.—Chromite in serpentine, diallage, antimony! senarmontite ! 
kermesite! valentinite, stibnite. 

Hutu Townsuip, Ottawa County.—Apatite, hornblende, titanite, 
tourmaline, barite, fluorite, jasper (Chelsea). 

HuNTERSTOWN.—Scapolite, sphene, vesuvianite, garnet, brown tour- 
maline ! 

INVERNESS.—Bornite, chalcocite, pyrite. 

JONQUIERE Townsuip.— Beryl. 

LAKE Sr. Francis.—Andalusite in mica schist. 

Lrxrps.—Dolomite, chalcopyrite, gold, chlorttovd, chalcocite, bor- 
nite, pyrite, steatite. 

MAIsONNEUVE TownsuiP, Berthier County.—Samarskite, beryl, 
muscovite. 

_MiLxe Istes.—Labradorite/ menaccanite, hypersthene, andesite, 
zircon. 

MontTreAu.— Calcite, augite, sphene in trap, chrysolite, natrolite, 


‘dawsonite, sodalite, acmite. 


Morin.—Sphene, apatite, labradorite. 

Mount ALBERT.—Chrysolite. 

OrrorD.—White garnet, chrome garnet, millerite, serpentine, 
pyroxene. 

PoRTAGE DU Fort.—Rensselaerite. 

Porron.—Chromite, steatite, serpentine, amianthus. 

RovuceMontT.—Augite in trap. 

Sr. ARMAND.—Micaceous iron ore with quartz, epidote. 

St. Francois Beauce.—Gold, platinum, iridosmine, menaccan- 
ite, magnetite, serpentine, chromite, soapstone, barite. 

ST. JEROME.—Sphene, apatite, chondrodite, phlogopite, tourmaline, 
zircon, garnet, molybdenite, pyrrhotite, wollastonite, labradorite. 

St. Norberr.—Amethyst in greenstone, 

SHERBROOKE.—At Suffield mine, albite/ native silver, argentite, 
chalcopyrite, blende. 

STUKELEY.—Serpentine, verd-antique / schiller spar. 

Surron.—JMJagnetite in fine crystals, hematite, rutile, dolomite, 
magnesite, chromiferous fale, bitter spar, steatite. 

TEMPLETON TOWNSHIP, Ottawa County.—Apatite / rutile, titan- 
ite, scapolite, tourmaline (bIk.), hematite (Llaycock mine), wollaston- 
ite, pyroxene, zircon, vesuvianite ! phlogopite! chrysotile, hornblende, 
prehnite, wilsonite, chabazite, stilbite, uralite, 

THETFORD.— Chrysotile / 

Urton.—Chalcopyrite, malachite, calcite. 

VAUDREUIL.—Limonite, vivianite. 

WAKEFIELD Townsuip, Ottawa County, — Apatite’ titanite, 
pyroxene, garnet, zircon, vesuvianite, scapolite, phlogopite, calcite 
(blue), spinel, tourmaline (blk). 

YAMASKA.—Sphene in trap, 


400 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


PROVINCE OF ONTARIO. 


ARNPRIOR.—Calcite. 

BatsaM LAKE.—Molybdenite, scapolite, quartz, pyroxene, pyrite. 

Batuurst.—Barite, black tourmaline, perthite (orthoclase), perister- 
ite (albite), bylownite, pyroxene, wilsonite, scapolite, apatite, titanite. 

BRANTFORD.—Sulphuric acid spring (4°2 parts of pure sulphuric 

acid in 1,000). 
*  BrockvitLE.—Pyrite. 

Bruce Mines on Lake Huron.— Calcite, dolomite, quartz, chalco- 
pyrite, chalcocite. 

BuRGEss. —Pyroxene, albite, mica, corundum, sphene, chalcopyrite, 
apatite, black spinel / spodumene (in a bowlder), serpentine, biotite. 

CALABOGIE LAKE.—Tremolite. 

CaPE IrpPpERWASH, Lake Huron.—Oxalite in shales. 

CLARENDON.— Vesuvianite, tourmaline. 

CREDIT River (forks of the).—Red celestite. 

DaALHousi£.—Hornblende, dolomite. 

DELORO.— Arsenopyrite! gold, calcite, chalcodite. 

DrummonpD.—Labradorite. 

ELIZABETHTOWN.—Pyrrhotite, pyrite, calcite, magnetite, talc, phlo- 
gopite, siderite, apatite, Ai 

ELMSLEY. —Pyroxene, sphene, feldspar, towrmaline, apatite, biotite, 
zircon, red spinel, chondrodite. 

Frrzroy.—Amber, brown tourmaline in quartz. 

GRAND CALUMET ISLAND.—Apatite, phlogopite! pyroxene! horn- 
blende, sphene, vesuvianite! serpentine, tremolite, scapolite, brown 
and black tourmaline! pyrite, loganite. 

Hieu Fauus or THE MADAWASKA.—Pyrovene / hornblende. 

INNISKILLEN.—Petroleum. 

JACKFISH LAKE, Huronian Mine.—Sylvanite. 

Kineston.— Celestite. 

Lac prs Cuarts, Island Portage.—Brown tourmaline / pyrite, cal- 
cite, quartz. 

Lanark.—Raphilite (hornblende), serpentine, asbestus, perthite 
(aventurine feldspar), peristerite. 

LANSDOWNE.— Celestite, vein 27 in. wide, and fine crystals, rens- 
selaerite, sphalerite, wiisonite, labradorite. 

Lirrre RrEAv.—Celestite (fibrous). 

Mapoc.—Magnetite. 

MARBLE Laks, Barrie Township. —Meneghinite, galena. 

MARMORA. —Magncetite, chalcolite, serpentine, garnet, epsomite, 
hematite, steatite, arsenopyrite, gold. 

McN as. —Hematite, barite. 

MICHIPICOTEN ISLAND, Lake Superior.—Domeykite, niccolite, gen- 
thite, chalcopyrite, native copper, native silver, chalcocite, galenite, 
amethyst, calcite, stilbite, analcite; at Maimanse Bay, Coracite, chal- 
cocite, chalcopyrite, native copper. 

NEwsorovucu.—Chondrodite, graphite. 

PAKENHAM. —Hornblende. 

PERTH.—Apatite in large beds, phlogopite. 

Ross Townsuip, Renfrew County.—Apatite, titanite, hornblende, 
pyroxene, orthoclase, scapolite, chrysotile, molybdenite, molybdite. 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 401 


Sr. ApELE.—Chondrodite in limestone. 

St. IenacEe IsLaAnD.— Calcite, native copper. 

SEBASTOPOL Township, Renfrew County.—Apatite/ titanite! zir- 
con! hornblende, orthoclase, microcline, scapolite, pyroxene, calcite. 

SitveR Isier, Lake Superior.—Argentite, native silver, galenite, 
niccolite, chalcocite, malachite. 

SoutH Crosspy.—Chondrodite. 

SyDENHAM.—Celestite. 

TERRACE Cove, Lake Superior.—Molybdenite. 

VERONA (near).—Black tourmaline. 

WALLACE Minz, Lake Huron.—Hematite, nickel ore, nickel vitriol, 
chalcopyrite. 


PROVINCE OF NEW BRUNSWICK. 


ALBERT Co.—Hopewell on Shepody Bay, gypsum, manganese 
ores; Albert mines, near Hillsboro’, albertite (largely exported) ; 
Shepody Mountain, alunite in clay, calcite, pyrite, manganite, psilo- 
melane, pyrolusite, gypsum (quarried), anhydrite (with the gypsum). 

CARLETON Co.— Woodstock, chalcopyrite, hematite, limonite, wad. 

CHARLOTTE Co.—Campobello, at Welchpool, blende, chalcopyrite, 
bornite, galenite, pyrite; at head of Harbor de Lute, galenite; Deer 
Island, on west side, calcite, magnetite, quartz crystals; Digdighash 
River on west side of entrance, calcite / (in conglomerate), chalcedony; 
at Rolling Dam, graphite; Grand Manan, between Northern Head 
and Dark Harbor, agate, amethyst, apophyllite, calcite, hematite, heu- 
landite, jasper, magnetite, natrolite, sti/bite; at Whale Cove, calcite / 
heulandite, laumontite, stilbite; sem?-opal / ; Wagaguadavic River, at 
entrance, azurite, chalcopyrite, in veins, malachite. 

GLOUCESTER Co.—Téte-a-Gouche River, eight miles from Bathurst, 
chalcopyrite (mined), oxide of manganese / formerly mined. 

Kines Co.—Sussex, near Cloat’s mills, on road to Belle Isle, ar- 
gentiferous galenite; one mile north of Baxter’s Inn, hematite in 
crystals, limonite; on Capt. McCready’s farm, selenite! ; at Upham, 
manganese ores, gypsum. 

ReEsTIGoucHE Co.—Belledune Point, calcite! serpentine, verd-an- 
tique ; Dalhousie, agate, carnelian. 

Sr. Joun Co.—Black River, on coast, calcite, chlorite, chalcopyrite, 
hematite! Brandy Brook, epidote, hornblende, quartz crystals; Carle- 
ton, near Falls, calcite; Chance Harbor, calcite in quartz veins, chlo- 
rite in argillaceous and talcose slate; Little Dipper Harbor, on west 
side, in greenstone, amethyst, barite, quartz crystals; Moosepath, 
feldspar, hornblende, muscovite, black tourmaline; Musquash, on 
east side harbor, copperas, graphite, pyrite; at Shannon’s, chrysolite, 
serpentine; east side of Musquash, quartz crystais/ ; Portland at the 
Falls, graphite; at Fort Howe Hill, calctte, graphite ; Crow’s Nest, 
asbestus, chrysolite, magnetite, serpentine, steatite; Lily Lake, white 
augite ? chrysolite, graphite, serpentine, steatite talc; How’s Road, 
two miles out, epidote (in syenyte), steatite in limestone, tremolite ; 
Drury’s Cove, graphite, pyrite, pyrallolite? indurated talc; Quaco, at 
Lighthouse Point, large bed oxide of manganese; Sheldon’s Point, 
actinolite, asbestus, calcite, epidote, malachite, specular iron; Cape 


402 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


> 


Spenser, asbestus, calcite, chlorite, specular tron (in crystals); West- 
beach, at east end on Evans’s Farm, chlorite, tale, guartz crystals ; 
half a mile west, chlorite, chalcopyrite, magnesite (vein), magnetite ; 
Point Wolf and Salmon River, asbestus, chlorite, chrysocolla, chalco- 
pyrite, bornite, pyrite. 

Victor1a Co.—Tabique River, agate, carnelian, jasper ; at mouth, 
south side, galenite; at mouth of Wapskanegan, gypsum, salt spring; 
three miles above, stalactites (abundant); Quisabis River, blue phos- 
phate of iron, in clay. 

WESTMORELAND Co.—Bellevue, pyrite; Dorchester, on Taylor’s 
Farm, cannel coal; clay ironstone; on Ayer’s Farm, asphaltum, petro- 
leum spring; Grandlance, apatite, selenite (in large crystals); Mem- 
ramcook, coal (albertite); Shediac, four miles up Scadoue River, coal. 

YorkK Co.—Near Fredericton, Prince William mine, stibnite 
(mined), native antimony, jamesonite, berthierite; Pokiock River, 
stibnite, tin pyrites? in granite (rare). 


PROVINCE OF NOVA SCOTIA. 


ANNAPOLIS Co.—Chute’s Cove, apophyllite, natrolite; Gates’s Moun- 
tain, analcite, magnetite, mesolite/ natrolite, stilbite; Martial’s Cove, 
analeite! chabazite, heulandite ; Moose River, beds of magnetite ; 
Nictau River, at the Falls, bed of hematite; Paradise River, black 
tourmaline, smoky quartz / ; Port George, faréelite, laamontite, me- 
solite, stilbite; east of Port George, on coast, apophyllite containing 
gyrolite; Peter’s Point, west side of Stonock’s Brook, apophyllite / 
calcite, heulandite, Jaumontite/ (abundant), native copper, stilbite ; 
St. Croix’s Cove, chabazite, heulandite. 

ANTAGONISH Co.—College Lake, chalcopyrite; on St. George’s 
Bay, and elsewhere, gypsum, in thick strata. 


Carr Breton Co.—At Gabarus, molybdeniie, bismuth glance; at 


Loch Lomond, Salmon River, manganese ore; at Plaister Cove, 
Mabou, Port Hood, etc., gypsum ; near Sydney, copper ores. 
CoLcHESTER Co.—Five Islands, East River, barite, calcite, dolo- 
mite (ankerite), hematite, chalcopyrite; Indian Point, malachite, 
magnetite, red copper, tetrahedrite; Pinnacle Islands, analeite, calcite, 
chabazite/ natrolite, siliceous sinter; Londonderry, on branch of Great 
Village River. barite/ ankerite, hematite, limonite, magnetite ; Cook’s 
Brook, ankerite, hematite; Martin’s Brook, hematite, limonite; at 
Folly River, below Falis, ankerite, pyrite; on high land, east of river, 
ankerite, hematite, limonite ; on Archibald’s land, ankerite, barvte, 
hematite ; Salmon River, south branch of, chalcopyrite, hematite ; 
Shubenacadie River, anhydrite, calcite, barite, hematite, oxide of 
manganese ; at the Canal, pyrite ; Stewiacke River, barite (in lime- 
stone; 300 tons mined in 1885); at Onslow, manganese ore. 
CUMBERLAND Co.—Cape Chiegnecto, barite ; Cape d'Or, analecite, 
avophyllite/ chabazite, faréelite, laumontite, mesolite, malachite, 
natrolite, native copper, obsidian, red copper (rare), vivianite (rare) ; 
Horse Shoe Cove, east side of Cape d’Or, analcite, calcite, stilbite , 
Isle Haute, south side, analcite, apophyllite! calcite, heulandite / 
natrolite, mesolite, stébite/ ; Joggins, coal, hematite, limonite; mala- 
chite and tetrahedrite at Seaman’s Brook ; Partridge Island, analcite, 


——_— | 


i ie a i a eh i ge Oe 


CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 403 


apophyllite! (rare), amethyst / agate, apatite (rare), calcite! chabazite 
(acadialite), chalcedony, cat’s-eye (rare), gypsum, hematite, heulan- 
dite / magnetite, stilbite/ ; Swan’s Creek, west side, near the Point, 
calcite, gypsum, heulandite, pyrite ; east side, at Wasson’s Bluff and 
vicinity, analeite! apophyllite! (rare), calcite, chabazite! (acadialite), 
gypsum, heulandite! natrolite / siliceous sinter ; Two Islands, moss 
agate, analcite, calcite, chabazite, heulandite ; McKay’s Head, anal- 
cite, calcite, heulandite, s¢/éccous sinter / ; at Amherst, manganese ore. 

Diesy Co.—Briar Island, native copper, in trap; Digby Neck, 
Sandy Cove and vicinity, agate, amethyst, calcite, chabazite, hematite ! 
laumontite (abundant), magnetite, sti/bite, quartz crystals ; Gulliver’s 
Hole, magnetite, stilbite / ; Mink Cove, amethyst, chabazite/ quartz 
crystals ; Nichols Mountain, south side, amethyst, magnetite! ; Wil- 
liams Brook, near source, chabazite (green), heulandite, stilbite, quartz 
crystal. 

ae Co.—Cape Canseau, andalusite. 

HAtirax Co.—Gay’s River, galenite in limestone; southwest of 
Halifax, garnet, staurolite, tourmaline; Tangier, gold / in quartz veins 
in clay slate, associated with auriferous pyrite, galenite, hematite, 
arsenopyrite, and magnetite; gold at Country Harbor, Fort Clarence, 
Isaac’s Harbor, Indian Harbor, Laidlow’s Farm, Lawrencetown, Sher- 
brooke, Salmon River, Wine Cove, and other places; at Hammond’s 
Plains and Musquodoboit, molybdenite. 

Hants Co.—Cheverie, oxide of manganese (in limestone), gypsum 
Petite River, gypsum, oxide of manganese ; Waiton, pyrolusite, man- 
gamite ; Teny Cape, manganese ores; Windsor, calcite, gypsum (great 
bed), with cryptomorphite (baronatrocalcite), howlite, glauber salt ; 
at Rawdon, stidnite, of which 758 tons (valued at $83,095) were ex- 
ported in 1885 ; at Teny Cape, manganese ore. 

Kines Co.—Black Rock, centrallassite, cerinite, cyanolite ; a few 
miles east of Black Rock, prehnite? s/dbite / ; Cape Blcmidon, on the 
coast between the cape and Cape Split, the following minerals occur 
in many places (some of the best localities are nearly opposite Cape 
Sharp): analcite! agate, amethyst! apophyliite! calcite, chalcedony, 
chabazite, gmelinite (lederite), hematite, heu/andi/e/ laumontite, mag- 
netite, malachite, mesolite, native copper (rare), natrolite / psilomelane, 
stilbite / thomsonite, fardelite, quartz ; North Mountains, amethyst, 
bloodstone (rare), ferruginous quartz, mesolite (in soil); Long Point, 
five miles west of Black Rock, heulandite, laumontite! stilbite ! ; 
Morden, apophyliite, mordenite ; Scott’s Bay, agate, amethyst, chalce- 
dony, mesolite, natrolite; Woodworth’s Cove, a few miles west of 
Scott’s Bay, agate! chalcedony ! jasper. 

LuNENBURG Co.—Chester, Gold River, gold in quartz, pyrite, mis- 
pickel; Cape la Have, pyrite; The ‘‘ Ovens,” gold, pyrite, arseno- 
pyrite ; Petite River, gold in slate. 

Prcrou Co.—Pictou, jet, oxide of manganese, limonite ; at Roder’s 
Hill, six miles west of Pictou, barite; on Caribou River, gray copper 
and malachite in lignite ; at Albion mines, coal, limonite; East River, 
limonite, hematite, magnetite, siderite, ankerite; on Sutherland’s R., 
siderite ; at Smithfield, argentiferous galenite. . 

QUEEN’s Co.— Westfield, gold in quartz, pyrite, arsenopyrite; Five 
Rivers, near Big Fall, gold in quariz, pyrite, arsenopyrite, limonite. 


404 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 


RicHMoOND Co,—West of Plaister Cove, barite and calcite in sand- 
stone ; nearer the Cove, calcite, fluorite (blue), siderite; gypsum in beds 
of great thickness (giving the name to Plaister Cove). 

SHELBURNE Co.—Shelburne, near mouth of harbor, garnets (in 
gnciss) ; near the town, rose quartz; at Jordan and Sable River, s/aw- 
rolite (abundant), schiller spar. 

SypNnEY Co.—Hillseast of Lochaber Lake, pyrite, chalcopyrite, side- 
rite, hematite; Morristown, epidote in trap, gypswm (making a cliff of 
200 feet, near Ogden’s Lake). 

YARMOUTH Co.—Cream Pot, above Cranberry Hill, gold in quartz, 
pyrite ; Cat Rock, Fourchu Point, asbestus, calcite, 


PROVINCE OF BRITISH COLUMBIA. 


Carr1Boo District.—Native gold, galena. 

On FRAZER RIvER.—Gold, argentiferous tetrahedrite, cerargyrite, 
cinnabar. 

OminicA District.—Native gold, argentiferous galenite, native 
silver, silver-amalgam. 

Howe’s Sounp.—Bornite, molybdenite, mica. 

"TExapDA Ip.—Magnetite. 

SHuswaP LAKE.—Bismuthinite. 


NEWFOUNDLAND. 


ANTONY’s IsLAND.— Pyrite. 

CATALINA HARBOR.—On the shore, pyrite / 

CHALKY H1Lu.—Feldspar. 

CorpPER ISLAND, one of the Wadham group.—Chailcopyrite. 

CoNCEPTION BAay.—On the shore south of Brigus, bornite and gray 
copper in trap. 

Bay oF IsuAnps.—Southern shore, pyrite in slate. 

Lawn.—Galenite, cerargyrite, proustite, argentite. 

PLACENTIA Bay.—At La Manche, two miles eastward of Little 
Southern Harbor, galenite/ ; on the opposite side of the isthmus from 
Placentia Bay, barite in a large vein, occasionally accompanied by 
chalcopyrite. 

SnHoaL Bay.—South of St. John’s, chalcopyrite. 

Trinity Bay.—Western extremity, barite. 

HARBOR GREAT St, LAWRENCE.—West side, fluorite, galenite. 


DETERMINATION OF MINERALS, 405 


V. DETERIMNATION OF MINERALS. 


In the determination of minerals, no one order in the sue- 
cession in which characters should be examined answers for 
all minerals, or even for all of the same section of species. 

The points to be first examined are: Hardness, which 
- may be tried by the point of a knife-blade, if a file or scale 
of hardness is not at hand; and fwsibility before the blow- 
pipe, with other blowpipe reactions; and, in the case of 
species of unmetallic lustre, solubility or not in hydrochloric 
acid (HCl), the dilute acid serving to test effervescence 
from the escape of carbonic acid (carbon dioxide, CO,), and 
the strong acid, to ascertain whether the mineral gelatinizes 
or not, and other points already explained. 

For species having a metallic lustre, the order of easiest 
application is generally, after trials of hardness, fusibility, 
and blowpipe reactions: Color; sectility, which distin- 
guishes argentite, amalgam, and some native metals from 
other species of metallic lustre; streak, whether metallic 
or not, and the color of the powder or rubbed surface; 
specific gravity, care being taken that the specimen is pure; 
action of nitric acid; crystalline form and cleavage, a char- 
acter of the highest importance; optical characters, in spe- 
cies that transmit light when in thin slices. 

For species without metallic lustre, after trial of hard- 
ness, B.B. characters, and solubility in acid: Color, but 
with doubt of its value, as impurities often cause great 
variations; streak, when it is decidedly colored; specific 
gravily ; sectility, when perfect like that of wax, which 
distinguishes cerargyrite and a related species; crystalline 
form and cleavage; taste, in the case of soluble species; 
optical characters, which are always important, and may be 
the best available means. 

The following hints may be of service to the beginner in 
the science, by enabling him to overcome a difficulty in the 
outset, arising from the various forms and appearance of the 
minerals quartz and limestone. Quartz occurs of nearly 
every color, and of various degrees of glassy lustre to a dull 
stone without the slightest glistening. The common gray- 
ish cobble-stones of the fields are usually quartz, and others 


406 DETERMINATION OF MINERALS.,- 


are dull red and brown; from these there are gradual transi- 
tions to the pellucid quartz crystal that looks like the best 
of glass. Sandstones are often wholly quartz, and the sea- 
shore sands are mostly of the same material. It is therefore 
probable that this mineral will be often encountered in 
mineralogical rambles. , 

Let the first trial of specimens obtained be made with a 
file, or the point of a knife, or some other means of trying 
the hardness; if the file makes no impression, there is rea- 
son to suspect the mineral to be quartz; and if on breaking 
‘it, no regular structure or cleavage plane is observed, but it 
breaks in all directions with a similar surface and a more or 
less vitreous lustre, the probability is much strengthened 
that this conclusion is correct. The blowpipe may next be 
used; and if there is no fusion produced by it in a careful 
trial there can be little doubt that the specimen is in fact 

uartz. 

5 Calcite (calcium carbonate), including limestone, is 
another very common species. If the mineral collected is 
rather easily impressible with a file, it may be of this spe- 
cies; if it effervesces freely when placed in a test-tube con- 
taining dilute hydrochloric acid, and is finally dissolved, the 
probability of its being carbonate of lime is increased; if 
the blowpipe produces no trace of fusion, but a brilliant 
light from the fragment before it, but little doubt remains © 
on this point. Crystalline fragments of calcite break with 
three equal oblique cleavages. 

Familiarized with these two Protean minerals by the 
above and other trials, the student has already surmounted 
the principal difficulties in the way of future progress. 
Frequently the young beginner who has devoted some 
time to collecting the differently colored stones in his 
neighborhood, on presenting them for names to some prac- 
tised mineralogist, is a little disappointed to learn that, 
with two or three exceptions, his large variety includes 
nothing but limestone and quartz. He is perhaps gratified, 
however, at being told that he may call this specimen yel- 
low jasper, that red jasper, another flint, and another horn- 
stone, others chert, granular quartz, ferruginous quartz, 
chalcedony, prase, smoky quartz, greasy quartz, milky 
quartz, agate, plasma, hyaline quartz, quartz crystal, basa- 
nite, radiated quartz, tabular quartz, etc., etc.; and it is 
often the case, in this state of his knowledge, that he is 


DETERMINATION OF MINERALS. 40% 


best pleased with some treatise on the science in which all 
these various stones are treated with as much prominence 
as if actually distinct species; being loath to receive the un- 
welcome truth, that his whole extensive cabinet contains 
only one mineral. But the mineralogical student has already 
made good progress when this truth is freely admitted, and 
quartz and limestone, in all their varieties, have become 
known to him. 

The student should be familiar with the use of the blow- 
pipe and the reactions, as explained on pages 93 to 102; 
it would be still better if a fuller treatise on the subject 
had been carefully studied. He should be supplied with the 
three acids in glass-stoppered bottles; a fourth bottle con- 
taining hydrochloric acid diluted one half with water, for 
obtaining effervescence with carbonates; test-tubes; and 
also the ordinary blowpipe apparatus and tests, including 
platinum wire, platinum forceps, glass tube, ‘cobalt solu- 
tion,” litmus and turmeric paper, etc. 

Also the following: 

A small file, three-cornered or flat, for testing hardness. 

A knife with a pointed blade of good steel, for trying 
hardness. It may be magnetized, to be used as a magnet, 
though a good horseshoe magnet of small size is better. 

The series of crystallized minerals, constituting the scale 
of hardness (see page 67). Diamond and talc are least es- 
sential. 

Cutting pliers, for removing chips of a mineral for blow- 
pipe or chemical assay. 

A pocket-lens. 

A hammer weighing about two pounds, resembling a 
stone-cutter’s hammer, having a flat face, and at the oppo- 
site end an edge having the 
same direction as the handle. 
The handle should be made of 
the best hickory, and the mor- 
tise to receive it should be as 
large as the handle. A foot 
scale should be marked on the handle of the hammer, di- 
vided into inches, the smallest divisions needed. It will be 
often of use in getting out a yard-stick, or a ten-foot pole, 
for large measurements, A similar hammer, having the 
upper part prolonged to a blunt point, to be used like a 
pick, is often convenient. 


























408 DETERMINATION OF MINERALS. 


A hammer of half a pound weight, like the figure, to be 
used in trimming specimens. 

A small jeweler’s hammer, for trying the malleability of 
globules obtained by the blowpipe, and for other purposes, 
and a small piece of steel for an anvil. 

Two steel stone chisels, one six inches long, and the other 
three. When it is desired to pry open seams in rocks with 
the larger chisel, two pieces of steel plate should be provided 
to place on opposite sides of the chisel, after an opening is ob- 
tained; this protects the chisel and diminishes friction while 
driving it. 

For blasting, if this is desired: 

Three hand-drills, 18, 24, and 36 inches long, an inch in 
diameter. The best form is a square bar of steel, with a 
diagonal edge at one end. The three are designed to fol- 
low one another. 

A sledge-hammer of six or eight pounds weight, to use in 
driving the drill. 

A sledge-hammer of ten or twelve pounds weight, for 
breaking up the blasted rock. 

A round iron spoon, at the end of a wire fifteen or eigh- 
teen inches long, for removing the pulverized rock from 
the drill-hole. 

A crowbar, a pickaxe, and a hoe for removing stones and 
earth before or after blasting. 

Cartridges of blasting powder, to use in wet holes. They 
should one third fill the drill-hole. After the charge is put 
in, the hole should be filled with sand and gravel alone 
without ramming. If any ramming material is used, plas- 
ter of Paris is the best, which has been wet and afterwards 
scraped to a powder. 

Patent fuse for slow match, to be inserted in the car- 
tridge, and to lead out of the drill-hole. 


The table beyond is prepared especially to aid in instruc- 
tion, and comprises, with few exceptions, only the species 
that are described in large type through the work, exclusive 
of the hydrocarbon compounds. Before commencing with 
the table in the determination of a mineral, it is best to 
make the preliminary trials mentioned on page 405. More- 
over, the brief description of a species should be supple- 
mented, whenever a doubt arises, by turning to the full 
description in the earlier part of the book. 


DETERMINATION OF MINERALS, 409 


The following abbreviations are used in the table, in ad- 
dition to those explained on page 102. With reference to 
colors: 6xh, brownish; dkh, blackish; gnh, greenish; gyh, 
grayish; rdh, reddish. The acids: nz?¢., nitric acid; sulph. 
acid, sulphuric acid; HCl., hydrochloric acid; sulph., sul- 
phur or sulphurous acid. 

Reactions: gelatinizing with acid, see page 92; reaction 
for sulphur with soda, see page 101; blue or red color with 
cobalt solution, see page 98; hydrous, yielding water in a 
closed tube: anhydrous, not yielding water in a closed tube, 
or only traces, see page 98; B.B. lithiwm-red color, see page 
98; B.B. green flame due to boron, see page 99; coal is used 
for charcoal; fus. for fusible; infus. for infusible; sol. for 
soluble; st. for streak. 

In using the blowpipe it is important to remember that 
a trial of fusibility with the forceps, if not at once produc- 
ing fusion, should be made on a piece of the mineral not 
larger than the fourth of an ordinary pin-head, and it should 
be either oblong and slender, or thin, and be made to pro- 
ject considerably beyond the points of the forceps, lest the 
forceps carry off the heat, and cause a failure where there 
ought to be success. Further, it should be in mind, that 
in using charcoal, a white coating is always a consequence 
of burning it, since the ash from its own combustion is 
white. Again, before testing for sulphur by means of soda 
and a polished surface of silver, it 1s necessary to try the 
flame and the soda for sulphur. Gas-flame always con- 
tains traces of sulphur, and sometimes too much for safe 
conclusions in this trial. 

A mineralogist sometimes has occasion to measure dis- 
tances, and by the following method he may make himself 
quite an accurate odometer: 

Let him first find, or make, along a roadside, a measured 
distance of 800 to 1000 feet, and then walk it at his ordi- 
nary walking pace three or four times, and note the number 
of steps. He will thus ascertain the actual length of his 
pace, and also find that in his ordinary walk it does not 
differ much from thirty inches; it may bean inch or two 
less, or one, two, or three more than this. Now four times 
thirty inches is ten feet. If then, as he walks, he counts 
one for every fourth step, each unit in the count will stand 
for ten feet nearly, and 100 for 1000 feet nearly. If his 
pace is thirty-one inches, let him add a unit for every 


410 DETERMINATION OF MINERALS. 


thirty in the counting, or, which is the same thing, call his 
thirty thirty-one, and the needed correction will be made; 
or if his step is twenty-nine and one half inches, subtract 
one from every sixty in the counting, or in other words du- 
plicate the sixtieth. Or the correction may be made at the 
end of the pacing; if at 600, this number, after adding a 
thirtieth, becomes 620; and the distance would hence be 
6200 feet. With a little practice the counting may be 
carried on almost unconsciously, and when the thoughts 
are elsewhere; that is, unless there is a talking friend by 
one’s side. 7 

An instrument, called a pedometer, of the shape and size 
of a small watch, is to be had of instrument-makers, which, 
if carried in the waistcoat pocket, will do the registering 
for the pedestrian and note the distance, without any atten- 
tion on his part. But the odometer explained above, when 
once in working order, is always at hand; moreover, the 
pocket pedometer measures miles, and not feet or yards. 


SYNOPSIS OF THE ARRANGEMENT. 
I, ELEMENTS. 


(None of the species in the other subdivisions have the 
characters here enumerated:) 


. Lustre metallic; liquid. 

. Lustre metallic; malleable and eminently sectile. 

. Lustre metallic; brittle; B.B. on coal, wholly volatile, with no 
sulphurous fumes. . 

. Lustre metallic; brittle; H. = 1-2; leaves a trace on paper; B.B. 
on coal, infusible, no fumes or odor. 

. Unmetallic; burns readily with a blue flame. 

. Lustre adamantine; H. = 10. 


aon -. Weare 


II. MINERALS NOT ELEMENTS THAT B.B. ON 
COAL ARE WHOLLY VOLATILE. 


. Lustre metallic; streak metallic. 
. Lustre unmetallic; streak same as color. 


oe 


III. COMPOUNDS OF GOLD, SILVER, COPPER, 
LEAD, TIN, MERCURY, CHROMIUM, COBALT, 
MANGANESE: yielding, on heating, a malleable, or 


ee 


DETERMINATION OF MINERALS. All 


liquid (for mercury ores), metallic globule, or else 
affording a decisive blowpipe reaction proving the 
presence sof one or more of these metals. 


A. Yielding a malleable globule B.B. on coal with, if not 
without soda. 


1. Compounds of Gold. 
2. Compounds of Silver. 
3. Compounds of Copper. 
4. Compounds of Lead. 
5. Compounds of Tin. 


B. Yielding drops of mercury when heated with soda, 1 in 
2 closed tube. 


1, Compounds of Mercury. 


C. A decisive reaction with borax or salt of phosphorus 
for chromium, cobalt, or manganese. 


1. Compounds of Chromium. 
2. Compounds of Cobalt. 
8. Compounds of Manganese. 


IV. MINERALS OF METALLIC OR SUBMETALLIC 
LUSTRE, NOT INCLUDED IN PRECEDING 
DIVISIONS. 


1. Yielding fumes in the open tube or on coal, but not 
wholly vaporizable. 


A. Streak metallic. 
B. Streak unmetallic. 
a. Fumes sulphurous only. 
&. Fumes arsenical, with or without sulphurous. 


2. Not yielding fumes of any kind; streak unmetallic. 


A. B.B. easily fusible, giving a magnetic bead; lustre sub- 
metallic. 
B. Infusible, or nearly so. 
a. Reaction for i iron; anhydrous. 
5. Reaction for iron; hydrous. 
c. Reaction for chromium or titanium. 
d. Reaction for osmium with nitre. 


412 DETERMINATION OF MINERALS. 


V. MINERALS OF UNMETALLIC LUSTRE. 


1. Having an acid, alkaline, alum-like, or styptic taste. 


A. CARBONATES: Taste alkaline; effervescing with HCl. 

B. SULPHATES: No effervescence; reaction for sulphur 
with soda. 

C. NITRATES: With sulph. acid, reddish acrid fumes; no 
action with HCl; deflagrate. 

D. CHLORIDES: With sulph. acid, acrid fumes of HCl; 
no fumes with HCl. 

E. BORATES: No effervescence; reaction for boron when 

moistened with sulph. acid. 


2. Not having either of the above-mentioned kinds of 
taste. 


' A, CARBONATES: Effervescing with HCl. 

a. Infusible; assay alkaline after ignition. 

6. Infusible; become magnetic and not alkaline, on 
ignition. 

c. Infusible; B.B. on coal with soda, zinc oxide 
vapors. 

d. Infusible; B.B. on coal reaction for nickel. 

e. Fusible; assay alkaline after ignition. 


B. SULPHATES: Reaction for sulphur with soda. 
a. Fusible; assay alkaline after fusion. 
6. Fusible; reaction for iron. 
c. Infusible. 


C. ARSENATES: on coal arsenical fumes. 
D. SILICATES, PHOSPHATES, OXIDES. 


Species not included in the preceding subdivisions. 


I. STREAK DEEP RED, YELLOW, BROWNISH-YELLOW, GREEN, OR 
BLACK. 


A. Infusible, or fusible with difficulty. 
B. Fusible without much difficulty. 


II. STREAK GRAYISH OR NOT COLORED, 


1. Infusible. 


A. Gelatinize with acid, forming a stiff jelly. 

B. Not forming a stiff jelly; hydrous. 
a. Blue color with cobalt solution. 
6. Reddish or pink color with cobalt solution. 
c. Not blue or red with cobalt solution. 


DETERMINATION OF MINERALS. 413 


C. Not forming a stiff jelly; anhydrous. 
a. Blue color with cobalt solution. 
b. Not blue or reddish color with cobalt solution. 


2. Fusible with more or less difficulty. 


A. Gelatinize and form a stiff jelly. 

a. Hydrous; fuse easily. 

b. Hydrous; fuse with much difficulty. 

c. Anhydrous. 

a. No reaction for sulphur; no coating on coal. 
#8. Reacticn for sulphur with soda. 
B. Not gelatinizing. 

1. Structure eminently micaceous; folia tough, pearly, 
and H. of surface of folia not over 8'5; anhydrous 
or hydrous. 

2. Structure not eminently micaceous, 

a. Hydrous. 
a. No reaction for phosphorus, or boron. 
+. H.=1to8; lustre not at all vitreous. 
t+. H.=3°5-6'5; lustre of cleavage sur- 
face sometimes pearly; elsewhere 
vitreous. 
. Reaction for phosphorus or boron. 
hydrous. 
B.B. lithium-red flame. 
B.B. boron reaction (green flame). 
. B.B. reaction for titanium. 
B.B. reaction for fluorine or phosphorus, 
B.B. reaction for iron. 
. B.B. no reaction for iron; not of the pre- 
ceding subdivisiors. 


Eo 


b. 


. 
e 
° 


OH ONDBR 


I, ELEMENTS. 


1. Lustre metallic; liquid. 


MERCURY, p. 142. This is the only metallic mineral which is 
liquid at the ordinary temperature and atmospheric pressure. 


2. Lustre metallic; malleable and eminently sectile. 


GOLD, p. 122. G. = 15-19°5; yellow; fusible; not sol. in nitric acid 
or HCl, but sol. in aqua regia. 

PLATINUM, p. 139. G. = 16-19; nearly white; infusible; insol. in 
nitric acid. 

PALLADIUM, p.141. G.—=11°3-11°8; grayish-white; diff. fusible; 
sol. in. nitric acid. 

SILVER, p. 129. G.=10-11:1; white; fusible; sol. in nitric acid, 
and deposited again on copper. 


414 DETERMINATION OF MINERALS. 


COPPER, p. 145. G. = 8:84; copper-red; fus.; sol. in nitric acid, 
and the solution becomes sky-blue when ammonia is added. 
IRON, p. 189. G. = 7'3-7'8; iron-gray; attracted by the magnet. 


The only other mineral of metallic lustre that is also malleable and 
eminently sectile is argentite, a silver sulphide, along with two others 
of like composition but different crystallization. 


3. Lustre metallic; brittle; B.B. wholly volatile, but give 
off no sulphurous fumes; H. = 2-3°5, 


BISMUTH, p. 113. G.= 9°73; reddish-white; on coal a yellow coat- 
ing; fumes inod. 

cpuecapnaee p. 112. G.=66-6°7 tin-white; fumes dense wh., 
inod. 

ARSENIC, p.110. G. = 5:9-6; tin-white; fumes white, alliaceous. 

THLLURIUM, p. 108. G. = 6'1-6'3; tin-white; fus.; fumes white; 
flame green. 


The only other mineral that is wholly volatile, and also gives off 
no sulphurous fumes, is allemontite, an antimony arsenide. 


4, Lustre metallic; H. = 1-2; B.B. on coal infusible; no 
fumes. } 


GRAPHITE, p. 119. 


5. Lustre unmetallic; takes fire readily in the flame of a 
candle, and burns with a blue flame. 


SULPHUR, p. 106. 


6. Lustre adamantine; H. = 10. 
DIAMOND, p. 115. Easily scratches corundum or sapphire. 


Il. MINERALS, NOT ELEMENTS, THAT 
-ARE WHOLLY VOLATILE B.B. 
ON COAL. 


1. Lustre metallic; streak metallic; H.=1-2. 


TETRADYMITE, p. 114. G.='7'2-7°9; pale steel-gray; so soft as 
to soil paper; on coal white fumes; flame bluish green; sometimes 
sulph. odor; in open tube, a coating which fuses to white drops. 

BISMUTHINITE, p. 114. G.=6:4-7:2; whitish lead-gray; on coal 
yellow coating and sulph. odor. 

STIBNITE, p. 112. G.=4'5-4'52; lead-gray; on coal dense wh, 
fumes and wh. coating. 


DETERMINATION OF MINERALS. 415. 


2. Lustre unmetallic; streak same nearly as color, except in 
cinnabar, in which it is always bright red. H.=1-3. 
ORPIMENT, p. 111. Lemon yellow; on coal burns, odor alliaceous, 

REALGAR, p.111. Bright red; on coal burns, odor alliaceous. 

ARSENOLITE, p. 111. White; on coal, odor alliaceous. 

VALENTINITE, p. 113. White; on coal dense wh. fumes, inod. 

CINNABAR, p. 143. Red; in open tube, sulph. odor, coating of 
mercury globules. 

SALMITAK, p. 249, White; saline and pungent taste; on coal, fumes 
of ammonia. 


III. COMPOUNDS OF GOLD, SILVER, 
MERCURY, COPPER, LEAD, TIN, 
CHROMIUM, COBALT, MAN- 
GANESE, 


A. Yielding a malleable globule B.B. on coal, with or 
without soda. 


1. COMPOUNDS OF GOLD. 


Yield gold, or an alloy of gold and silver, B.B. on coal. 
The TELLURIUM ORES, pp. 129, 132, give a coating of drops of tel- 
lurous acid in open tube (p. 101). 


2. COMPOUNDS OF SILVER. 


B B. easily fusible; G. above 5; yield, with few exceptions, a glo- 
bule of silver (white and malleable) on coal, with soda, if not without; 
and, in the exceptions, silver globule obtained by cupellation. All 
have metallic lustre excepting cerargyrite, bromyrite, and iodyrite. 


a. EMINENTLY SECTILE. 


ARGENTITE, p. 131. G.=7:2-7°4; lustre metallic; H.= 2; on coal 
sulph, fumes. 

CHRARGYRITE, p. 134. H.=—1-2; G.=5-3-5'6; lustre like that 
of white, gray, or greenish to brownish wax; see also related spe- 
cies, p. 134, 


6. NOT SECTILE; ON COAL ODOROUS FUMES, 


SULPHIDES, p. 181. Gives sulph. odor. 
ARSENICAL ORES, p. 132. Alliaceous fumes. 
SELENIDES, p. 181. Horse-radish odor. 


Cc. NOT SECTILE; ON COAL FUMES OF ANTIMONY OR TELLURIUM, 


ANTIMONIAL ORES, pp. 132, 133. Dense white fumes of anti- 
mony; with also, if sulphur is present, sulph. fumes. 


416 DETERMINATION OF MINERALS, 


TELLURIDES, pp. 131, 132. In open tube coating which fuses to 
drops of tellurous acid. 

STROMEYERITE, p. 131. Contains copper, and requires cupellation 
in order to obtain a globule of silver. 


3. COMPOUNDS OF' COPPER. 


Unless iron is present, a globule of metallic copper is obtained with 
soda, if not without, on coal; with a nitric acid solution and ammonia 
in excess a bright blue color; moistened with HCl the blue flame of 
chloride of copper; and a clean surface of iron in the nitric solu- 
tion becomes coated with copper. 


1. METALLIC LUSTRE. 


pel de titi pp. 146-148. On coal or in open tube sulph. fumes; 
H. = 2-4. 

ARSENIDES, SELENIDES, p. 149; H.— 2-4, 

ANTIMONIAL SULPHIDES, pp. 149, 150; H.=2-4°5. 


2. LUSTRE UNMETALLIC; B.B. NEITHER ON COAL NOR IN OPEN 
TUBE ANY ODOROUS FUMES; NO TASTE. 


CUPRITE, p. 151. H.=3'5-4; G.=5-8-6:2; isometric; deep red, 
streak bnh-red. 

ATACAMITE, p. 150. Darkish bright green, streak gnh; BB. on 
coal f08e6, coloring O.F. azure-blue, with a green edge; easily sol. 
in acids. 

PHOSPHATES, p. 158. H.= 2-5; G.=2°8-4'5. 

MALACHITE, p. 154. H.=—3-4; G.=3'7-4; light to deep green; 
effervesces with HCl. 

AZURITE, p.156. H.=3'5-4:5; G.= 3:5-3°'9; deep blue; effervesces 
with HCl. 

DIOPTASE, p. 156. H.=5; G.=3°25-3°35; never fibrous; emerald- 

een; B.B. infusible. 

CHRYSOCOLLA, p. 157. Bluish green; B.B. infusible; amorphous. 


3. LUSTRE UNMETALLIC; B.B. ON COAL, OR IN CLOSED TUBE, ODOROUS 
FUMES OF ARSENIC OR SULPHUR, OR REACTION FOR SULPHUR. 


ARSENATES, p. 153. On coal arsenical fumes; H. = 2-3. 
CHALCANTHITE, p. 152. Blue; taste nauseous; astringent. 
Also Stromeyerite, Stannite, Bournonite give reactions for copper. 


4. COMPOUNDS OF LEAD. 


Yield B.B. on coal a dark lemon-yellow coating; finally, with 
soda, if not without, a globule (metallic and malleable) of lead is ob- 
tained; but by continued blowing with O.F. the lead all goes off in 
fumes, leaving other more stable metals (silver, etc.) behind. Sul- 
phurous, selenious, and tellurous fumes easily obtained either on coal 
or in an open tube from the sulphide, selenide, tellurides; and arseni- 
cal or antimonial fumes from ores containing arsenic or antimony. 
None have taste; none have H. above 4. 


DETERMINATION OF MINERALS. Al? 


1. LUSTRE METALLIC. 


GALENITE,, p. 160. H. = 2°5; G. = 7°2-7°7; cleavage cubic emi- 
nent ; lead-gray, streak same ; in open tube sulph. 

SELENIDES, TELLURIDES, ANTIMONIAL and ARSENI- 
CAL SULPHIDES, pp. 160-164. 


2. LUSTRE UNMETALLIC ; NO ODOROUS FUMES, OR REACTION FOR 
SULPHUR. 


MINIUM, p. 165. Bright red, streak same. 

CROCOITE, p. 166. Monoclinic; bright red, streak orange-yellow; 
B.B. with salt of phosphorus emerald-green bead. 

PYROMORPHITE, p. 167. Hexagonal, 6-sided prisms; bright 
green, brown, rarely orange-yellow; streak white. B.B. fuses 
easily, coloring flame bluish green. 

VANADINITE, p. 168. Hexagonal prisms, like pyromorphite; 
G. = 6°6-7'2 ; yellow, bnh-yw, straw yellow. B.B. fuses easily, 
reaction for vanadium. 

CERUSSITE, p. 168. Orthorhombic, often in twins; H. = 3-3:'5; 
G. = 6°4-6°8; white, gyh; lustre adamantine; often tarnished to 

_ grayish metallic adamantine. LEffervesces in dilute nitric acid. 


8. UNMETALLIC ; REACTION FOR SULPHUR. 


ANGLESITE, p. 165. Orthorhombic; white, gyh; fuses in flame 
of candle; B.B. reaction for sulphur; no effervescence with acids. 


5. COMPOUNDS OF TIN. 

CASSITERITH, p. 176. H.=—6-7; G.=647:1; tetragonal; 
brown, gyh, ywh, black; B.B. infusible; on coal with soda a globule 
of tin, yield no fumes. 

Stannite, p. 176. A copper, iron, and tin sulphide, does not give 

B.B. a metallic malleable globule. 


B. Yields drops of mercury in closed tube with or 
without soda. 


COMPOUNDS OF MERCURY. 


CINNABAR, p. 148. H. = 2-2°5; G. = 8-9; rhombohedral; bright 
red, bnh red, gyh; streak scarlet. 

AMALGAM, p. 130. H. = 3-3'5; G. = 13-14; silver-white; yields 
silver B.B. on coal. 
A variety of tetrahedrite, p. 150, yields mercury. 


C. No malleable globule ; decisive reaction with borax or 
salt of phosphorus for chromium, cobalt, or manganese. 


at 


418 DETERMINATION OF MINERALS, 


1. COMPOUNDS OF CHROMIUM. 
Give with borax an emerald-green bead in both flames. 


CHROMITE, p. 197. H.=55; G.=4°3-4'5; isometric, often in 
octahedrons, massive ; submetallic ; bnh iron-black, streak brown ; 
B.B. on coal becomes magnetic; with borax, a bead which is 
emerald-green on cooling. 

CROCOITE, p. 166. H. = 2:5-3; G. = 5:9-6:1; monoclinic ; bright 
red, streak orange; B.B. fuses very easily, on coal globule of lead, 
and with salt of phosphorus emerald green bead. Phenicochroite 
and Vauquelinite are other lead chromates. 


2. COMPOUNDS OF COBALT. 


Give a blue color with borax after, if not before, roasting. 
[When much nickel or iron is present the blue color is not ob- 
tained; and species or varieties of this kind are not here included. | 


1. LUSTRE METALLIC. 


COBALTITE, p. 182. H. =5'5; G. = 6-63; isometric and pyrito- 
hedral; rdb silver-white, streak grayish black; B.B. on coal sulph. 
and arsen. fumes, and a magnetic globule. . 

SMALTITH, p. 181. H. =5'5-6; G. = 6°4-7°2; isometric; tin- 
white, streak gyh black; B.B. on coal alliaceous fumes; most 
varieties fail to give the blue color immediately with borax, because 
of the iron and nickel present. 

LINNZ®AITEH, p. 181. H. =5°5; G. = 4°8-5; isometric; pale steel- 
gray, copper-red tarnish, streak bkh gray. B.B. on coal sulph. 
fumes. 


2. LUSTRE UNMETALLIC. 


ERYTHRITE, p. 184. H. = 1°5-2°5; G. = 2°95; monoclinic, one 
highly perfect cleavage, also earthy; rose-red, peach-blossom red, 
streak reddish; B.B. fuses easily; yields water. 

BIEBERITE, p. 185. <A cobalt sulphate. 

REMINGTONITES, p. 185. A hydrous cobalt carbonate. 


3. COMPOUNDS OF MANGANESE. 


Give an amethystine globule in O.F. with borax. [The globule 
looks black if too much of the manganese mineral is used, and with 
a large excess may be opaque. | 


1. GIVES OFF CARBONIC ACID WHEN TREATED WITH DILUTE HCl; 
LUSTRE UNMETALLIC. 


RHODOCHROSITE, p. 210. H. = 3°5-4°5; G. = 38°4-3°7; rose-red. 


Also manganese-bearing varieties of calcite, dolomite, ankerite, side- 
rite, all of which have the cleavage and general form of rhodochro- 
site ; when containing one per cent. or more of manganese they often 
turn black on exposure. 


DETERMINATION OF MINERALS. 419 


2. TREATED WITH HCl YIELDS CHLORINE FUMES. 


MANGANITE, p. 207. H.=—4; G. = 4'2-4:4; in oblong ortho. 

- rhombic prisms; grayish black, streak reddish brown ; lustre sub- 
metallic ; B.B. infusible; yields water. 

PSILOMELANE, p. 207. H. =5-7; G. =3°7-4°7; amorphous; 
black, streak brownish black ; submetallic; B.B. infusible; yields 
water. 

Wad is similar, but often contains cobalt. 

PYROLUSITE,, p. 206. H. = 2-2°5; G. = 4°82; in stoutish ortho- 
rhombic crystals; metallic; dark steel-gray, streak black or bluish 
black; B.B. infusible; yiclds no water. _ 

BRAUNITE and HAUSMANNITE (p. 207) are other anhydrous 
manganese oxides. 

FRANKLINITE, p. 197. H.=5°5-6°5; G. = 5-51; in isometric 
octahedrons and massive ; iron-black, streak dark reddish brown ; 
B.B. infusible ; but little chlorine with HCl; sometimes a little 
magnetic. 


8. COz oR Cl NOT GIVEN OFF WHEN TREATED WITH HCl; 
ANHYDROUS. 


RHODONITE, p. 268. H. =5°'5-6:5; G.=—3°4-3°68; rose-red ; 
B.B. fuses easily. 

TRIPLITE, p. 209. H. =5°5; G. = 3°4-3'8; brown to black; B.B. 
fuses very easily, globule magnetic; sol. in HCl. 

HELVITE, p. 278. H. = 6-6'5; G. = 3°1-3°3; in yellowish tetrahe- 
hedrons; B.B. fuses easily. 

SPHESSARTITE (Manganesian Garnet), p. 279. H. = 6°5-7;G. = 
3°7-4°4 ; in dodecahedrons and trapezohedrons; red, brownish red; 
B.B. fuses easily. 

TEPHROITE, p. 277. H. = 55-6; G.=— 44:12; orthorhombic ; 
aan to brown and gray; B.B. fuses not very easily; gelat. in 

Cl. 
Knebelite, p. 277, is related, and also gelatinizes. 

HAUERITE, p. 206. H. = 4; G. = 8°46; isometric; reddish brown, 
streak brownish red. B.B. yields sulphur, after roasting reaction 
for manganese. 

ALABANDITE, p. 206. H.=3:'5-4; G.=4; submetallic, iron- 
black; streak green; B.B. on coal sulphur, after roasting reaction 
for manganese. 

Vesuvianite, epidote, axinite, ilvaite, gothite, include varieties that 
give reaction for manganese, 


420 DETERMINATION OF MINERALS. 


IV. MINERALS OF METALLIC OR SUB- 
METALLIC LUSTRE NOT INCLUDED 
IN PRECEDING DIVISIONS. 


1. YIELDING FUMES IN THE OPEN TUBE OR 
ON COAL, BUT NOT WHOLLY VAPORIZABLE. 


A. STREAK METALLIC; H. = 1-2. 


MOLYBDENITE, p. 108. H. = 1-1°5; G. = 4°4-4'8; lead-gray, and 
leaves trace on paper; B.B. on coal sulphurous fumes. 

BISMUTHINITE, p. 114. H. = 2; G. = 6°4-7°2; lead-gray, whitish; 
B.B. on coal sulphurous fumes, and yellow bismuth oxide; sol. in 
hot nitric acid and a white precip. on diluting with water. 


B. STREAK UNMETALLIC. 


a. FUMES SULPHUROUS ONLY. 


PYRITE, p. 192. H. = 6-6:5; G. = 4°8-5°2; isometric, most com- 
mon in cubes, the faces of which sometimes smooth, often striated, 
the striee of adjoining faces meeting at right angles, often in pyrito- 
hedrons; pale brass-yellow, streak gnh black, bnh black; B.B. on 
coal, fuses to a magnetic globule. 

MARCASITE, p. 191. H. = 6-6°5; G. — 4.68-4'85; orthorhombic; 
pale bronze-yellow; streak gyh black, bnh black; B.B. like pyrite. 

PYRRHOTITE, p. 192. H. = 3°5-4:5; G. = 4:4-4°68; hexagonal; 
bronze-yellow, rdh; streak gyh black; slightly magnetic; B.B. 
fuses to a magnetic mass. 

MILLERITBH, p. 181. H. = 3-8°5; G. = 4°6-5°7; rhombohedral, 
usually in acicular or capillary forms, also in fibrous crusts; brass- 
yellow somewhat bronze-like; B.B. fuses to a globule, reacts for 
nickel. 

LINNGITEH, p. 181. H.=5°5; G.=—4°8-5 ; isometric ; pale steel- 
gray, copper-red tarnish; streak blackish-gray; B.B. on coal fuses 
to a magnetic globule, after roasting gives reactions for nickel, 
cobalt, and iron. 

SPHALERITH, p. 170. H.=3'5-4; G.—3°9-4:2; isometric; 
bright and easy dodecahedral cleavage when cryst.; lustre sub- 
metallic; color black ; streak nearly uncolored; nearly infusible 
alone and with borax; on coal a coating of zinc oxide. 


b. ARSENICAL FUMES, WITH OR WITHOUT SULPHUROUS. 


ARSENOPYRITB, p. 192. H.=—5-6; G.=6-6°4; orthorhombic; 
white, gyh, streak dark gyh black. In closed tube, red arsenic 


DETERMINATION OF MINERALS. 421 


Ae and metallic arsenic; B.B. on coal fuses to magnetic 

globule. 

GERSDORFFITE, p. 183. H.=5'5; G.=5-°6-6'9; isometric, py- 

. ritohedral; white, gyh, streak grayish black. In closed tube 
arsenic sulphide, on coal not magnetic, and reacts for nickel and 
often cobalt. 

NICCOLITE, p. 182. H.= 5-55; G.=‘%7'3-7'7; hexagonal; pale 
copper-red, streak pale bnh black ; in open tube, coating of arsen- 
ous acid; B.B. on coal no sulph. fumes, fuses to globule which re- 
acts for iron, cobalt and nickel. 

SMALTITE, p. 181. H.=5°5-6; G.=—6°4-7'2; isometric; tin- 
white ; streak gyh black ; on coal, no fumes of sulphur or only in 
traces. 


2, NOT YIELDING FUMES OF ANY KIND. 
STREAK UNMETALLIC. 


A. B.B. EASILY FUSIBLE, AND GIVING A MAGNETIC 
BEAD. LUSTRE SUBMETALLIC. 


ILVAITE, p. 285. H.=5°5-6; G.=3'7-4:2; orthorhombic; gyh 
iron-black, streak gnh or bnh black; gelat. with HCl. 

ALLANITE, p. 284. H.=5°5-6; G.=8-4'2; monoclinic; bnh 
pitch-black, streak gyh, bnh; B.B. fuses easily ; most varieties 
gelat. with HCl. 

WOLF RAMITE, p. 200. H.=5-5:5; G.=71-7°6; monoclinic ; 
gyh black or bnh black ; B.B. fuses easily, and reacts for iron, man- 
ganese, and tungsten. 


B. INFUSIBLE OR NEARLY SO. 
a. REACTION FOR IRON; ANHYDROUS; H.=5-6'5. 


MAGNETITE, p. 196. G.=4°9-5°2; isometric; iron-black; 
streak black; strongly magnetic. 

MENACCANITE, p. 195. G.= 45-5; rhombohedral; iron-black ; 
streak submetallic, black to bnh red; very slightly magnetic. 

HEMATITE, p. 198. G.=4°5-5°3; rhombohedral; gyh iron-black, 
in very thin splinters or scales blood-red by transmitted light ; 
streak red; sometimes slightly magnetic. 

NARTITE, p. 194. Same as hematite, but isometric. 

TANTALITE, p. 202. G.='7-8; orthorhombic ; iron-black, streak 
rdh brown to black. 

FRANKLINITE, p. 197. H.=5:5-6°5; G.=4°8-5'1 ; octahedral, 
massive ; iron-black ; streak dark rdh brown ; slightly attracted by 
magnet; with soda reaction for manganese. 

COLUMBITE, p. 207. G.=—5°4-6°5; orthorhombic ; iron-black, 
gyh black, streak dark red to black, often with a bluish steel- 
like tarnish. 

SAMARSKITE, p. 221. H.=5°5-7; G.=5°6-5°8; velvet-black, 
pitch-black ; streak dark rdh brown ; B.B. glows; fuses with difli- 
culty. 


422 DETERMINATION OF MINERALS. 


b. REACTION FOR IRON ; HYDROUS ; LUSTRE SUBMETALLIC. 


LIMONITE, p. 198. G.=38°6-4; not in crystals ; massive, often 
stalactitic and tuberose with surface sometimes highly lustrous ; 
often subfibrous in structure; black, bnh black; streak bnh yellow, 
which becomes red on heating. 

GOTHITE, p. 199. G.=4-0-4:4; orthorhombic; also fibrous and 
massive; bkh brown; streak bnh yeliow. 

TURGITE, p. 199. G.=3°6-4'68; fibrous and massive, looking 
like limonite ; black, rdh black, streak red ; in closed tube decrepi- 
tates, which i is not the case with gothite and limonite. 


C. REACTION FOR CHROMIUM OR TITANIUM. 


CHROMITE, p. 197. H.=5-5; G.=4'3-4°6; isometric; submetal- 
lic ; bnh iron-black, streak brown ; B.B. with borax gives a bead 
which on cooling is chrome-green. 

RUTILE, p. 179. H.= 6-6: D: G.= 4:18-4:25 ; black, streak bnh ; 
reacts for titanium. Black varieties of brookite (p. 180), submetallic 
in lustre, give same reaction. 

Huxenite, p. 222; yttrotantalite, p. 221; eschynite, p. 222; Serguson- 
ate, p. 221; and perofskite, p. 180, are submetallic in lustre. 


d. HEATED WITH NITRE IN A MATRASS YIELDS FUMES oF OSMIUM. 


IRIDOSMINE, p. 141. H.=6-7; G.—19-21°2; in small scales 
from auriferous or platiniferous sands; tin-white, gyh. 


V. LUSTRE UNMETALLIC. 


1. MINERALS HAVING AN ACID, ALKALINE, 
ALUM-LIKE, OR STYPTIC TASTE. 


A. CARBONATES: Taste alkaline; effervescing with HCl. 


NATRON, p. 249. Efiloresces on exposure. 
TRONA, p. 249. Docs not effloresce. 


B. SULPHATES: No effervescence; reaction B.B. on coal with 
soda for sulphur. 


MASCAGNITE, p. 250. Yields ammonia. 

MIRABILITH, p. 246. Monoclinic, crystals stout; taste cool, 
saline, bitter; B.B. flame deep yellow. 

EPSOMITES, p. 224. Orthorhombic, crystals ordinarily slender, 
spicule-like; taste bitter and saline; B.B. flame not yellow. 

ALUNOGEN, p. 216. Taste like common alum. 

KALINITE, MENDOZITE and other alums, p. 217. 

MELANTERITE, p. 199. Green; taste styptic ; reacts for iron. 

OCHALCANTHITE, p. 152. Blue; reacts for copper. 


DETERMINATION OF MINERALS, 423 


MORENOSITE, p. 185. Green; reacts for nickel. 
BIEBERITE, p. iss, Reddish ; reacts for cobalt. 
GOSLARITE, p. 472... White ; ‘reacts for zine. 
JOHANNITE, p. 188. Emcrald- green, reacts for uranium. 


C. NITRATES: With sulphurie acid, reddish acrid fumes; no 
action with hydrochloric acid; deflagrate. 


NITRE, p. 247. Not efflorescent. Strong deflagration, 
NITRATINE, SODA-NITRE, p. 248. Efflorescent, 
NITROCALCITE,, p. 234. -. Deflagration slight. 


D. CHLORIDES: With sulphuric acid acrid fumes of HCl; no 
fumes with HCl. 


SALMIAK, p. 249. Taste saline, pungent ;.on coal, cvaporates ; 
with soda, odor of ammonia. 

SYLVITE, p. 243. Taste saline; B.B. flame purplish. 

aa or COMMON SALT, p. eo Taste saline ; B.B. flame 
yellow 


E. BORATES. No effervescence with acids; B.B. reaction for 
boron, when moistened with sulphuric acid. 


SASSOLITE, p. 109. Taste feebly acid ; B.B. very fusible. 
BORAX, p. 246. Taste sweetish alkaline; B.B. puffs up. 


2, MINERALS NOT HAVING AN ACID, ALKA- 
LINE, ALUM-LIKE OR STYPTIC TASTE. 


A. CARBONATES: Effervescing with HCl. 
A. INFUSIBLE ; ASSAY ALKALINE AFTER IGNITION. 


CALCITE, p. 234. H. under 3°5; G.= 2°5-2.72; RA R= 105° 5’, 
with three easy cleavages parallel to &; colors various ; effevesces- 
readily with cold HCl; anhydrous. 

ARAGONITE,, p. 237. H.=3°5-4; G.= 2°94; orthorhombic, cleav- 
age imper fect; otherwise like calcite. 

DOLOMITE, p. 2388. H.= 3°5-4 ; G.=2°8-2:9; rhombohcdral, 
R A &=106° 15’; colors various; effervesces but slightly with cold 
HCl, unless finely pulverized; anhydrous. 

MAGNESITE, p. 226. H.=—3°5-4:5; G.= 3-31; rhombohedral, 
BA R=107° 29’; white, ywh, gyh; ‘effervesces but slightly with 
cold HCl; anhydrous, 

HYDROMAGNESITE, p. 224. H.=—1-35; G.=2142:18; 
bydrons, . 


424 DETERMINATION OF MINERALS. 


B. INFUSIBLE; BECOME MAGNETIC AND NOT ALKALINE AFTER 
IGNITION. 


SIDERITE, Pp. 208. H.=3'5-4:5; G.=3°7-3:9; rhombohedral, 
R:R=107'; cleavage as in calcite ; becomes brown on exposure, 
changing to limonite. . 

ANKERITE, p. 204. H.=3°5-4; G.=2°9-31; RA R=106° 7; 
becomes brown on exposure. 


Some kinds of calcite and dolomite contain iron cnough to become 
magnetic on ignition. 


C. INFUSIBLE ; B.B. ON COAL WITH SODA, COATING OF ZINC OXIDE. 


SMITHSONITE, p. 172. H.=5; G.=44°5; rhombohedral like 
calcite; RA R=107° 40’; crystals often an acute rhombohedron ; 
anhydrous. 

HYDROZINCITE, p. 173. H.= 2-25; G.=8'6-3°8 ; white, gyh, 
ywh, often earthy ; reacts for zinc ; hydrous. 


D. INFUSIBLE; B.B. ON COAL REACTION FOR NICKEL. 


ZARATITE (Emerald Pe p. 185. H.=38. Emerald green, 
streak paler. 


E. FUSIBLE; ASSAY ALKALINE AFTER IGNITION. 


WITHERITE, p. 241. H.— 3-3°75 ; G@.— 4:29-4:35 ; orthorhombic ; 
‘white, ywh, eyh; B.B. fuses easily, flame ywh green ; anhydrous. 
STRONTIANITEH, p. 242. H.=3'5-4; G.=3°6-3° 72 ; orthorhom- 
bic ; pale green, gray, ywh, ie B.B. fuses only on thin edges, 

flame bright red ; anhydrous. 
BARYTOCALCITE, p. 242. Monoclinic. G.=36-3°66 ; B.B. 
nearly like witherite. 


Other carbonates are the Lead Carbonate, p. 168, and Copper ‘Car- 
bonates, p. 154, 156, included severally under the heads of LEAD and 
CopPER, on pages 416, 417. 


B, SULPHATES or SULPHIDES: Reaction for Sulphur 
with Soda. 


A. FUSIBLE; ASSAY ALKALINE AFTER FUSION. 


BARITE, p. 240. H.=2°5-3:5; G.=4°3-4:'72; orthorhombic; 
white, ywh, gyh, bluish, brown ; B.B. decrepitates and Be 
flame ‘yellowish green ; anhydrous. 

CELESTITE, p. 242. H.=—3-3'5; G.=3'9-3:98; orthorhombic; 
white, pale blue, rdh ; B.B. fuses ; ’ flame red; : anhydrous. | 

ANHYDRITE, p. 230. H.—3-3° Bs G.= 2.9-3°0 ; orthorhombic, 
with three rectangular and casy cleavages ‘differing but slightly ; 
white, bluish, gyh, rdh, red; B.B. fuses, see reddish ycllow. 

GYPSUM, p. 229. H.=1°5- B34 GS 2-3-2 ‘385; monoclinic, one 
perfect, pearly cleavage ; white, ‘er ay, but also brown, black from 


DETERMINATION OF MINERALS. 425 


impurities ; B.B. yields much water, becomes white and crumbles 
easily. ‘ 
B. FUSIBLE ; REACTION FOR IRON. 


COPIAPITE, p. 200. H.=1°5; G.=2:14; yellow; on coal, be- 
comes magnetic ; hydrous. 
_ Haiiynite, p. 294, also gives the sulphur reaction with soda. 


C. INFUSIBLE, OR NEARLY SO. 


ALUMINITE, p. 218. H.=1-2; G.=1°66; adheres to the tongue; 
white ; B.B. blue with cobalt solution. Alunite, p. 198, is similar, 
but H.= 4, and G.= 2°58-2°%5. 

SPHALERITE, p. 170. H.=3'5-4; G.=—3°9-4:2; isometric, easy 
dodecahedral cleavage when cryst.; light to dark resin-ycllow and 
brown to gyh white; B.B. on coal, coating of zinc oxide. 


C. ARSENATES: Arsenical fumés on coal. 


SCORODITE, p. 208. H.=—3°5-4; G.= 3°1-3°3; orthorhombic; 
leek-green to liver-brown; B.B. fuses easily, flame blue, and with 
soda gives a magnetic bead; on coal alliaceous fumes; in HCl 


sol. 

PHARMACOSIDERITE, p. 208. H.=2°5; G.= 2°9-8; cubes 
and tetrahedrons; dark green, bnh, reddish; B.B. same as for 
scorodite. 

PHARMACOLITE, p. 234. H.=2-2°5; G.=2'6-2°75 ; wh, gyh, 
rdh ; monoclinic with one eminent cleavage ; B.B. fuscs, flame 

. ne on coal, alliaccous fumes; after ignition assay alkaline; in 

Cl sol. 


D. SILICATES, PHOSPHATES, OXIDES: SPECIES NOT 
INCLUDED IN THE THREE PRECEDING SUBDIVI- 
SIONS. 


I. Streak deep red, yellow, brownish yellow, green or black. 


A. INFUSIBLE, OR FUSIBLE WITH MUCH DIFFICULTY. 


HEMATITE, p. 198.  Rhombohedral ; red to black; streak red; 
sae reaction for iron; magnetic after ignition in R.F.; anhy- 

rous. 

LIMONITE, p. 198. Brownish and ochre-yellow to black ; streak 
brownish-yellow ; B.B. gives off water, turns red, becomes mag- 
netic in R.F. 

TURGITH, p. 199. Brown to black; streak red; B.B. gives off 
water ; decrepitates ; becomes magnetic in R.F. 

FERGUSONITE,, p. 221. Brownish black; infusible. 

ZINCITE, p. 171. Red; streak orange ; B.B. on coal, zine oxide 
coating, and coating moistened with cobalt solution, green in R.F, 


426 DETERMINATION OF MINERALS, 


‘B. FUSIBLE WITHOUT MUCH DIFFICULTY. . 


WOLFRAMITE, p. 200. Grayish to brownish black ; streak dark 
reddish brown to black; lustre submetallic; G.= 7 1-7-55. BB. 
fuses easily, and becomes magnetic ; reaction for tungsten. 

VIVIANITE, p. 202. Blue to green (to white); streak bluish white; 
G.=20-2'7; H.=1'5-2, hydrous; B.B. fuses easily to magnetic 
globule, colori ing flame bluish green. 

TORBERNITE, p. 187. Bright green, square tabular micaccous 
crystals ; streak paler green ; “H. = 2-2° 5; hydrous; yields a glob- 

. ule of copper with soda. 

SAMARSKITE, p. 221. H.=5°5-6; G.=5-6-5'8; velvet-black ; 
streak dark reddish brown; B.B. fuses on the edges. 


II. Streak grayish or not colored. 


1. INFUSIBLE. 
A. GELATINIZE WITH ACID, FORMING A STIFF JELLY. 


CHRYSOLITE, p. 277. Yellow-green to olive-green, looking like 
glass; H.=— 6:7; G.=3-3-3°5; B.B. reacts for iron, becomes mag- 
netic; anhydrous. 

CHONDRODITE, p. 303. H.=6-6'5; G.=3'1-3°25; pale yellow 
to brown, and garnet-red ; lustre vitreous to resinous ; B.B. reac- 
tion for iron and fluorine; anhydrous. 

ALLOPHANE, p. 318. H.=3; G.=18-41 ‘9; always amorphous, 
never granular in texture ; bluish, greenish ; B.B, infus., a blue 
color with cobalt solution; hydr ous. 


Willemite, Calamine, Sepiolite, fuse with great difficulty, and are 
included under fusible gelatinizing species, pp. 428, 429. 


B. NOT FORMING A STIFF JELLY WITH ACID; HYDROUS. 
a. Blue with cobalt solution (owing to presence of aluminium).: 


WAVELLITE, p. 220. H.=38°25-4; G.= 2°3-2°4; white to green, 
brown; B.B. bluish green flame after moistening with sulph. acid. 
LAZULITE, p. 218. H.=56; G.=3-3'1; blue; B.B. green 

flame, especially after moistening with sulph. acid; hydrous. 
TURQUOIS, p. 219. H.=6; G.=2°6-2°85 ; sky-blue, pale green ; 
B.B. flame green. 
KAOLINITE, p. 232.. H.=1-2; G.=2°4-2°65; white when pure ; 
feel greasy; B. B. flame not ereen. 
GIBBSITE, p. 213. H.=2°5-3°5; G.=2°3-2:4; white, grayish, 
- greenish; B.B. flame not green; soluble in strong sulph. acid. 
DIASPORE, p. 213. H.=6°5-7; G.=—3°3-3°5; in thin foliated 
crystals, plates or scales ; white, ‘ercenish, brownish ; B.B. flame 
not green; soluble in sulphuric acid after ignition. 


b. Pale red or pink color, with cobalt solution (owing to presence 
of magnesium). 


BRUCITE, p. 223. H.= 2°5; G.=2'3-2'45; pearly, white, ereen- 
ish; foliaceous or fibrous and. flexible; B.B. after ignition, alkaline. 


OE 


DETERMINATION OF MINERALS, 427% 


c. Not blue or red with cobalt solution. 


OPAL, p. 259. H.=5'5-6°5; G.=1°9-2°3; B.B. with soda soluble 
with effervescence. 

GENTHITE, p. 332. H.=—3-4; G.=2'4; pale green, yellowish; 
B.B. with borax a violet bead, becoming gray in R.F. owing to 
nickel; decomp. by HCl. 

CHRYSOCOLLA, p. 157. H.=2-4; G.= 2-2:24; pale bluish green 
to sky-blue; B.B. flame emerald-green, and with soda on coal 
globule of copper. 

The micas, chlorites, chloritoid, and serpentine often fuse on their 
edges with much difficulty. 


C. NOT FORMING A STIFF JELLY; ANHYDROUS. H.=5 to 9, 


a. Blue color with. cobalt solution. 


CORUNDUM, p. 211. H.=9; G.=4; rhombohedral; blue, white, 
red, gray, brown. 

CHRYSOBERYL, p. 215. H.= 8°5; G.= 3:7; orthorhombic; gray- 
ish green, to emerald-green, brown. ° 

TOPAZ, p. 309. H.=8; G.=3°'5; in rhombic prisms with perfect 
ay cleavege, rarely columnar; white, wine-yellow, and other 
shades. 

RUBELLITE, p. 305; H.—75; G.=83; in prisms of 3, 6, or 9 

- gides; rose-red;: reaction for boron. 

ANDALUSITE, p. 306. H.=75; G.=3°2; orthorhombic; always 
in prismatic crystals, often tessellated within, J A = 93°; grayish 

_ white to brown. 

FIBROLITE, p. 307. H.= 6-7; G.= 3:2; orthorhombic columnar 
or fibrous forms and prismatic crystals with brilliant diag. cleavage. 

CYANITE, p. 308. H.= 5-7 (greatest on extremities of crystals); 
G.= 3°6; in long or short prismatic triclinic crystallizations, often 
bladed prisms; pale blue to white and gray. 

LEUCITE, p. 295. H.=5°5-6; G.= 2°5; often in trapezohedral 
crystals; white, gyh. 


b. Not giving a blue or reddish color with cobalt solution; H.= 
8 to 5. 


SPINEL, p. 213. H.= 8; G.= 3°5-4:1; in octahedrons of red, green- 
ish, gray, black colors; sometimes dodecahedral. Gahnite is simi- 
lar, but with borax on coal, gives reaction for zinc, 

BERYL, p. 274. H.= 75-8; G. = 2°6-2°7; always in hexagonal prisms; 
pale bluish and yellowish green to emerald-green, also resin yellow 
and white, no distinct cleavage. 

ZIRCON, p. 281. H.=—7'5; G.=4-4°75; tetragonal, and often in 
square prisms; lustre adamantine; brown, gray. 

STAUROLITE, p. 291. H.=7; G.= 3°4-3°'8; in prisms of 123°, 
and often in cruciform twins; no distinct cleavage; brown, black, 


gray. 

QUARTZ, p. 253. H.=7; G.= 2°6; often in hexagonal crystals 
with pyramidal terminations; of various shades of color. OPAL, 
p. 259, is in part anhydrous, 


428 DETERMINATION OF MINERALS, 


MONAZITE, p. 222. H.= 5-5:5; G.= 4°9-5°3; in small brown im- 
bedded monoclinic crystals, with perfect basal cleavage; B.B, flame 
bluish green when moistened with sulph. acid. 

RUTILE, p.179. H.= 6-65; G.=4°15-4'25; tetragonal; reddish 
brown to brownish red, green, black; B.B. reaction for titanium. 
BROOKITE and OCTAHEDRITE, p. 180, are similar, except in crystal- 
line forms, and-.G. in brookite 4°0-4°25, in octahedrite 3°8-8°95. 

PEROF'SKITH, p. 180. H.=5°'5; G.= 4-411; yeilowish, brown, 
black; cubic and octahedral forms; B.B. reaction for titanic acid. 

ENSTATITE, p. 264. H.=5'5; G.=38'1-3°3; in orthorhombic pris- 
matic and fibrous forms with J A J = 88° 16’, also foliated; whitish, 
grayish, brown, bronzite and hypersthene contain iron. Anthophyl- 
lite is similar, but J A £= 125°, and it fuses on the edges with great 
difficulty. 


Tolite, apatite, scheelite, euclase, fuse with much difficulty, and eu- 
clase gives some water in closed tube when highly ignited. 


2. FUSIBLE WITH LITTLE OR MUCH DIFFICULTY. 
A. Gelatinize and afford a Stiff Jelly. 


a. Hydrous; fuse easily. 


DATOLITE, p. 311. H.=— 5-55; G.=2°8-8; monoclinic; white, 
greenish, yellowish; crystals glassy, stout, sometimes massive and 
porcellanous, never fibrous; B.B. fuses easily, reaction for boron. 

NATROLITE, p. 821. H.=5-5'5; G. = 2°3-2°4; in slender rhombic 
prisms, and divergent columnar; white, ywh, rdh, red; B.B. fuses 
very easily. 

SCOLECITBH, p. 321. H.=5-5'5; G.= 2°16-2°4; cryst. much like 
natrolite, but twinned, with converging striz on ?@-2 as in figure on 

. 299; B.B. sometimes curls up, fuses very easily. 

GMELINITE, p. 323. H.= 4°5; G.= 2-22; in small and short hex- 
agonal or rhombohedral cryst.; B.B. fuses easily. 

PHILIPPSITS, p. 324. H.=44°5; G.= 2°2; in twinned crystals; 

’ B.B. fuses rather easily. 

LAUMONTITE, p. 315. H.=3°5-4; G.= 2°2-2°4; white, reddish; 
crystals become white and crumbling on exposure to the air; B.B. 
fuses rather easily. 


Pectolite (p. 315) and Analcite (p. 322) imperfectly gelatinize. 


b. Hydrous; fuse with much difficulty. 


CALAMINE, p. 174. H.= 4'5-5: G.= 8°15-3'19; white, greenish, 
bluish; orthorhombic in crystals; B.B. fus. with great difficulty, re- 
action for zinc and none for iron; hydrous. 

SEPIOLITE, p. 328. White; soft and almost clay-like, also fibrous; 
B.B. fuses with difficulty, with cobalt solution reddish; hydrous. 
PYROSCLERITE, p. 338. H.=3; G.= 2°74; micaceous; B.B. 

fuses on thin edges. 


DETERMINATION OF MINERALS. 429 


. ec, Anhydrous. 
a. NO REACTION FOR SULPHUR; NO COATING ON COAL. 


NEPHELITS, p. 293. H.= 55-6; G.= 2°5-2°65; hexagonal prisms 
and massive; vitreous, with greasy lustre; white, ywh, gyh brown, 
rdh; B.B. fuses rather easily. 

WOLLASTONITE, p. 265. H.= 45-5; G.= 2°75-2°9; white, gyh, 
rdh, bnh; B.B. fuses easily. 

SODALITE, p. 294. H.= 55-6; G.= 2°13-2°4; white, blue, reddish; 
in dodecahedrons and massive; B.B. fuses not very casily. 

WILLEMITE, p. 173. H.=5:5; G.=38°9-4°3; white to greenish, 
reddish, brownish; B.B. glows and fuses with difficulty; reaction 
for zinc and none for ir on; anhydrous. 


f. REACTION FOR SULPHUR B.B. WITH SODA. 


HAUYNITE, p. 294. H.= 5°5-6; G.= 2°4-2°5; blue, greenish; iso- 
metric, in dodecahedrons, octahedrons; B.B. fuses with some difli- 
culty. 

DANALITE,, p. 278. H.=5:5-6; G.= 3°427; isometric; flesh-red to 
Bray. B.B. fuses rather easily, and gives reaction for manganese 
and zinc. 


B. Not Gelatinizing. 


1, STRUCTURE EMINENTLY MICACEOUS, SURFACE OF FOLIA 
MORE OR LESS PEARLY; H. OF SURFACE OF FOLIA 
NOT OVER 3°5; ANHYDROUS OR HYDROUS. 


MUSCOVITE, BIOTITH, PHLOGOPITH, LEPIDOLITE, LE- 
PIDOMELANE: for distinctions see pp. 287-291. Anhydrous, 
or affording very little water; B.B. fuse with difficulty on thin 
-edges, excepting lepidomelanc, "which fuses rather more easily. 

MARGARODITE, DAMOURITE, pp. 290, 335. Much like com- 

- mon mica, but more pearly and greasy to the feel, folia not elastic; 
giving a little water in the closed tube; color usually whitish. 

PENNINITE, RIPIDOLITE, PROCHLORITE, p. 339. Usually 
bright or deep green, blackish green, reddish, rarcly white; folia 
tough, inelastic; B.B. diff. fus., reaction for iron and yield much 
water; partially decomposed by ‘acids, 

VERMICULITE, JEFFERISITE, pp. 338,339. Brown, yellowish 
brown, green; exfoliate remarkably; yield much water, 

MARGARITE, p. 841. H.=3°5-4'5 (highest on edges); G.= 2°99; 
white, ywh, rdh; folia somewhat brittle; B.B. fuses on thin edges; 
yields a little water, 

TALC, p. 325. H =—1-1'5; G.= 2°5-2°8; pearly and very greasy to 
the touch; white pale gr een, gray; B.B. very difficultly fusible, yields 
usually traces of water; reddish with cobalt solution. 

PYROPHYLLITE, p. 328. Similar to talc; but B.B. exfoliates re- 

markably; blue with cobalt solution. 

FAHLUNITE, p. 336, has often a morc or less distinct micacecous 
structure. 


430 DETERMINATION OF MINERALS, 


Autunite, p. 188, has a mica-like basal: cleavage; but 1t occurs in 
small square tables of a bright yellow color. Déallage, p. 267, has 
a structure nearly micaceous. Serpentine is sometimes nearly mni- 
caceous, but the folia are not easily separable and are brittle. Chio-. 
ritoid has a perfect basal cleavage, but folia very brittle, and cleav- 
age less easily obtained than in the preceding; and moreover the 
mineral is infusible. 


2. STRUCTURE NOT MICACEOUS. 
a. Hydrous. 


a. No REACTION FOR PHOSPHORUS, OR BORON. 


+ Hardness, with the exception of a variety of serpentine, 1 to 3; 
lustre not at all vitreous. 


CHLORITES, p. 837. H.=2-2°5. Here fall the massive granular 
chlorites, olive-green to black -in color, of the species penninite, ri- 
pidolite, p ochlor tte ; B.B. reaction for i iron, fuses with difficulty; 
yields much water. 

ViARMICULITE, p. 338. H.=1-1'5. Granular massive forms of 
vermiculite. 

TALC, p. 336. H.=1-1°5. Here falls steatite (soapstone) or mas- 
sive tale, of white to grayish green and dark green color, granular 
to cryptocrystalline in texture. B.B. fuses with great ditficulty, 
and yields only traces of water; no reaction for iron, or only slight. 

PYROPHYLLITBE, p. 328. Grayish white, massive or slaty; B.B. 
like the crystallized in its difficult fusibility and little water tea: 
but does not exfoliate. 

SERPENTINE, p. 329. H.=2°5-4; G.= 2°36-2° 55; olive-green; 
ywh green; blackish green, white; B.B. fuses with ‘difficulty on 
thin edyes; yields much water. 

PINITH, p. 334. H.= 2°5-3°5; G.= 2°6-2°85; lustre feebly waxy; 
gray, enh, bnh. B.B. fuses; yields water. 

DAMOURITES, p. 335. Same as crystallized, p. 403, but in massive 
aggregation of scales, 


{+ Hardness 3°5 to 6:5; lustre often pearly on a cleavage surface, 
but elsewhere vitreous. 


PREHANITE, p. 317. H.= 6-65; G.= 2°8-3; pale green to white; 
crystals often barrcl-shaped, made of grouped tables; B.B. fuses 
very easily; decomp. by HCl. 

PHECTOLITH, p. 315. H.=5; G.=2°68-2°8; white; divergent 
ree or acicular; B.B. fuses very casily; gclatinizes imperfectly 

ith HCl. 

APOFHYLLITS, p. 316. H.=4°5-5; G. = 2'3-2'4; white, enh, ywh, 
rd; tetragonal, one perfect pearly ‘cleavage transverse to prism; 
B.B.fuses + very easily: a fluorine reaction; decomp. by HCl. 

CHABAZITE, p. 322. H.= 4-5;G.=2-2° 2: rhombohedral, vitreous; 
white, rdh; B.B. fuses casily; decomp. by HCl. 

HARMOTOMS, p. 823. H.=4:5; G.=244; white, ywh, rdh; 
crystals twins, usually cruciform; B.B. fuses not ver y “easily; vitre- 
ous in lustre; decomp. by HCl. 

STILBITE, p. 324. H.=3°5-4; G.= 2-2°2; white, ywh, red; crystal- 


DETERMINATION OF MINERALS. 431 


lizations often radiated-lamellar; one perfect pearly cleavage; B.B. 
exfoliates, fuses easily; decomp. by HCl. 
HEULANDITE, p. 825. H.=3°5-4; G.= 2°2; in oblique crystals, 
with one perfect pearly cleavage; B. B. same as for stilbite. 
HUCLASE, p. 311. H.= ‘7-5; G.= 3:1; in glassy transparent mono- 
clinic crystals; B.B. fuses with great difficulty; gives water in closed 
tube when strongly ignited. 


Prehnite, apophyllite, chabazite, harmotome, heulandite, and euclase 
never occur in fibrous forms. Epidote and zoisite (p. 407), like euclase, 
give out water when strongly ignited. 


B REACTION EITHER FOR PHOSPHORUS OR BORON. 


VIVIANITE, p. 203. H.=1°5-2; G. = 2°55-7; monoclinic with one 
perfect cleavage; white, blue, green; B.B. fuses very easily, the flame 
bluish green, a gray magnetic globule; in HCI sol. 

ULEXITE, p. 231. H.=1; G.= 1°65; white, silky, in fine fibres; 
B.B. fuses very easily, and moistened with sulph. acid flame for an 
instant green, owing to the boron present; little sol. in hot water. 
PRICEITE (p. 212) is in texture and color like chalk; similar to 
ulexite in green flame B.B. 


Borax and Sassolite are other soft minerals containing boron, but 
these have tas/e, 


6. Anhydrous. 
a. B.B., the flame lithium-red. 


SPODUMENE,, p. 269. H.=6°5-7; G.= 3:13-3:19; white, gyh, gnh 
white, reddish, emerald-green, monoclinic (like pyroxene), with 
TeheL= 8T~, and perfect cleavage parallel to J and 7-7; B.B. swells 
and fuses. 

PETALITE, p. 269. H. = 6-65; G.= 2 “4 2°5; white, gray, rdh, 

nh; B.B. becomes glassy and fuses only on the edges. 

AMBLYGONITE, Pe 2182 HSS 6; Gry 3-3'1,; mountain green, 

yh, white, bnh; B.B. fuses very casily, reaction for fluorine. 

TRIPHYLITE, p. 208. H. =5; G, = 3°5-3°6; greenish gray, bluish, 
often bnh black externally; B.B. fuses very easily, globule mag- 
netic; with soda, manganese reaction. 

LEPIDOLITE, p. 289. H.= 25-4; G@. = 2°8-8; micaccous, also 
scaly-granular; rose-red, pale violet, ‘white, gyh; B.B. fuses easily: 
after fusion gelat. with HCl. Some biotite, p. 291, gives the lithia 
reaction. 


f. B.B. boron reaction (green flame). 


TOURMALINE, p. 304. H.=7; G. =2°9-8°3; rhombohedral, 
prisms with 8, 6, 9 sidcs, no longitudinal or other distinct cleavage; 
black, blue black, green, red, rarely white; lustre of dark var. 
resinous; B.B. fusion easy for ‘dark var. and diff. for light. 

AXINITE, p. 286. H. = 65-7; G. = 3-27; triclinic, sharp-cdged, 
glassy crystals; rich brown to pale brown and grayish, B.B. fuses 
readily; with borax violet bead. 

BORA ITE, p. 225. H.=7; G.=2°97; isometric; white, gyh, 
guh; lustre vitreous; fuses easily, coloring flame green. 


Danburite, p. 286, is another boron silicate. 


432 DETERMINATION OF MINERALS. 


y. Reaction for titanium. 


TITANITE, p. 312. H. = 5-5'5; G. = 3°4-8°56; monoclinic; usually 
in thin sharp-edged crystals; brown, ywh, pale green, black; 
lustre usually subresinous; B.B. fuses with intumescence. 


6. Reaction for fluorine or phosphorus. 


CRYOLITE, p. 216. H. = 2°5; G. = 2°9-3; white, rdh, bnh; fases 
in the flame of a candle; soluble in sulph. acid which drives off 
hydrogen fluoride, a gas that corrodes glass. 

FLUORITE, p. 227. H. = 4; G. = 8-3°25; isometric, with perfect 
octahedral cleavage, and massive; white, wine-yellow, green, pur- 
ple, rose-red, and other bright tints; phosphoresces; when heated, 
decrepitates; B.B. fuses, coloring the flame red; after ignition, 
‘alkaline. 

Lepidolite (p. 289), Amblygonite (p. 218), give a fluorine reaction. 

APATITBH, p. 232. H. = 4°5-5; G. = 2°9-3°25; often in hexagonal 
prisms; pale green, bluish, yellow, rdh, bnh, pale violet, white ; 
B.B. fuses with difficulty, moistened with sulph. acid and heated, 
flame bluish green from presence of phosphorus; sometimes reaction 
for fluorine. 


e. Reaction for iron. 


GARNET, p. 278. H. = 65-75; G. = 3°15-4'3; isometric, usually 
in dodecahedrons and trapezohedrons, also massive, never fibrous or 
columnar; red, bnh red, black, cinnamou-red, pale green to emerald- 
green, white. B.B. dark-colored varieties fuse easily, and give 
iron reaction, but emerald-green var. almost infusible; a white to 
yellow massive garnet is hardly determinable without chemical 
analysis. 

VESUVIANITE (Idocrase), p. 282. H.=—65; G. = 8°35-3°45; 
tetragonal and often in prisms of four or cight sides, never fibrous; 
brown to pale green, ywh, bk; B.B. fuses more easily than garnet; 
reaction for iron. 

EPIDOTE, p. 283. H.= 6-7; G. = 3°25-3°5; in monoclinic cryst. 
and massive, rarely fibrous; unlike amphibole in having but one 
cleavage direction; ywh green, bnh green, black, rdh, yellow, dark 
gray ; B.B. fuses with intumescence ; contains some water, but 
separated only at a high temperature. 

AMPHIBOLE, dark varieties including hornblende, actinolite, and 
other green to gray and black kinds, p. 270. H. = 5°6; G@. = 8-3-4, 
monoclinic, in short cr long prisms, often long fibrous, lamellar, and 
massive, prisms usually four or six sides, J A [= 124}°, cleavage 
par. to J; B.B. fusion easy to moderately difficult. 

ANTHOPHYLLITEH, p. 273, like hornblende, but orthorhombic ; 
bnh gray to bnh green, sometimes lustre metalloidal; B.B. fuses 
with great difficulty. 

PYROXENE, augite, and all green to black varieties, p. 265. H.= 
5-6; G. = 3°2-85; monoclinic, in short or oblong prisms, Jamellar, 
columnar, not often long, fibrous or asbestiform, prisms usually 
with four or eight sides, JA I = 87° 5’, cleavage par. to J; B.B. as 

‘ in hornblende. 


DETERMINATION OF MINERALS. 433 


HYPERSTHENE, p. 264. H. = 5-6; G. = 3°39; cryst. nearly as in 
pyroxene, but orthorhombic, usually foliated massive, also fibrous ; 
bnh green, gyh black, pinchbeck-brown; B.B. fuses with more or 
less difficulty. Bronzite, p. 244, is similar and almost infusible. 

IOLITEH, p. 287. H. = 7-7°5, G. = 2°6-2°7; orthorhombic; blue to 
blue violet; looks like violet-blue glass; B.B. fuses with much 
difficulty. 

Tourmaline, much Titanite, and Iivaite (p. 285), B.B. give iron 
reaction. 


¢. No reaction for iron. 


SCHEELITE, p. 232. H. =4°5-5; G. = 5°9-6°1; tetragonal; ywh, 
gnh, rdh, pale yellow; lustre vitreous-adamantine; fuses on the 
edges with great difficulty. — 

SCAPOLITSES, p. 292. H. =5 5-6; G. = 2°6-2°74, tetragonal, often 
in square prisms; white, gray, gnh gray; B.B. fuses casily with 
intumescence. 

ZOISITE, p. 285. H. = 6-6:5; G. = 3 1-3°4; orthorhombic, oblong 
prisms and lamellar massive, cleavage in only one direction ; like 
epidote in giving out some water when highly ignited. 

AMFHIBOLH, white var. (tremolite), p. 270. Same as for other 
amphibole (above), except in color; B.B. fuses. 

PYROXENE, white var., p. 266. Same as for other pyroxene (above), 

_ except in color; B.B. fuses. 

ORTHOCLASE, p. 300. H. = 6-6°5; G. = 2°4-2°62; monoclinic, 
stout cryst., and massive, never columnar, two unequal cleavages, 
the planes at right angles with one another, and cleavage surfaces 
never finely striated, as seen under a pocket lens or microscope; 
white, gray, flesh-red, bluish, green; B.B. fuses with some difficulty, 

ALBITE, p. 299, OLIGOCLASE, p. 299. H. = 6; G. = 2:56-2:72, 
triclinic, but cryst. as in orthoclase, except that the two cleavage 
planes make an angie of 934° to 94°, and one of them has the surface 
striated ; white usually, flesh-red, bluish; B.B. fuse witb a little 
difficulty; not acted on by acids. 

LABRADORITE, p. 298. H. =6; G. = 2°66-2°76; triclinic, like 

’ albite in cryst., and nearly in cleavage angle, 98° 20’, and in striz 
of surface; white, flegh-red, bnh red, dark gray, gyh brown; B.B. 
fuses easily; decomposed by HCl with difficulty. 

ANORTHITE, p. 298. H. = 6-7; G. = 2°66-2°78; cryst. and striz 
as in albite, cleavage angle 94° 10’; white, gyh, rdh; B.B. fusion 
difficult; decomposed by HCl with separation of gelat. silica. 

MICROCLINE, p. 300. Very near orthoclase in all characters, but 
triclinic, cleavage angle differing only 16’ from a right angle, and 
surface of most perfect cleavage striated, but strize exceedingly 
fine, often difficult to detect with a good pocket lens, and requiring 
the aid of a polariscope; color white, gray, flesh-red, often green. 

For optical distinctions of FELDsPARs, see beyond. 

BUCLASE, p. 311. H.=%75; G@.=31; in monoclinic crystals, 
with one perfect diagonal cleavage , pale green to white, bnh; 

- transparent; becomes electric by friction. 


28 


ON ROCKS.—PETROLOGY. 


THE term Petrology, signifying the science of Rocks, em- 
braces the study of the origin and transformation of rocks, 
as well as their classification and distinctive characters. 
The last of these subjects alone is included under the term 
Petrography. 

Rocks are made up of minerals. A few kinds consist of 
a single mineral alone: as, for example, limestone, which 
may be either the species calcite or dolomite; guartzyte 
(along with much sandstone), which is quartz ; and felsyte,. 
which is orthoclase. But even these simple kinds are sel- 
dom free from other ingredients, and often contain visibly 
other minerals. Nearly all kinds of rocks are combinations 
of two or more minerals. They are not definite compounds, 
but indefinite mixtures, and hardly less indefinite than the 
mud of a mud-flat. The limits between kinds of rocks 
are consequently ill-defined. Granite graduates insensibly 
into gneiss, and gneiss as insensibly into mica schist and 
quartzyte, syenyte into granite, mica schist into hornblende 
schist, granite also into a compact porphyry-like rock, and 
quartz- -trachyte ; and so it is with many other kinds. The 
fact is a chief source of the difficulty in studying and de- 
fining rocks, and especially the crygtalline kinds. The 


different rocks are not species in the sense in which this 


word is used in science, but only kinds of rocks. 


I. CONSTITUENTS OF ROCKS. 


The following is a list of the chief constituent minerals 
and of the more important of the accessory species : 


A. SILICEOUS SPECIES AND SILICATES.  ~ 


1. Quartz, tridymite, opal. 
2. The FELDSPARS: all NON-FERRIFEROUS ; all ALKALINE (alkali- 
bearing, containing either potash or soda) except anorthite; orthoclase, 


=  —_ a 


CONSTITUENTS OF ROCKS. 435 


microcline, oligoclase, labradorite, the more abundant; andesine, anor- 
thite, albite, and intermediate kinds, less so. 

3. OTHER NON-FERRIFEROUS ALKALINE MINERALS: Jeucite, con- 
taining 17 to 21 p. c. of potash, with the atomic ratio that of andesine; 
nephelite (eleolite), 15 to 16 p. c. of soda with 5 or 6 of potash; soda- 
lite, 20 to 25 p. ¢. of soda ; some scapolites, 5 to 6 p. c. of soda; spodu- 
A about 5 p. c. of lithia. 

| OTHER NON-FERRIFEROUS ALKALINE MINERALS: THE SAUSSUR- 
ITE-ZOISITE GROUP: light-colored, tough, jade-like minerals, derived 
(as shown by remains of crystalline forms and cleavage) from the 
alteration mainly of labradorite or anorthite, and in the change becom: 
ing of high specific gravity (8-3°4); contain 4 to 5 p. ec. of alkali, 
nearly all of it soda, and 40 to 50 p. c. of silica. See on Saussurite, 
p. 285. 

5. The MICAS: ALKALINE, AND CONTAINING MORE OR LESS IRON. 
Biotite is often styled magnesia-mica, although truly a potash mica 
like muscovite. Some muscovite, biotite, and other species contain 
lithia as well as potash. Gieseckile or pinite has the composition of a 
hydrous mica, but occurs only massive, and usually as a pseudomorph. 

6. ALKALINE FERRIFEROUS SPECIES: Acmite and egirite, near py- 
roxene in angie, 10 to 18 p. c. of soda; arfvedsonite and glaucophane, 
near hornblende, 5 to 9p. c. of soda, A few analyses of ordinary 
hornblende give 1 to 4 p. c. of soda. 

7. NON-ALKALINE FERRIFEROUS SPECIES: part of amphibole (horn- 
blende, smaragdite), pyrorene (augite, diallage, etc.) and garnet, with 
hypersthene, epidote, tourmaline, chrysolite, staurolite. 

8. NON-ALKALINE, NON-FERRIFEROUS SPECIES: enstatite (in part), 
cyanite, andalusite, fibrolite (sillimanite), 

9. HyDROUS NON-ALKALINE SPECIES : serpentine, tale, pyrophyllite, 
chlorite ; the first two magnesian, without iron or aluminium, ex- 
cept as impurity ; the third, aluminous and talc-like, without iron or 
magnesium; the fourth, containing iron, mangesium, and aluminium. 
. ae these silicates, tourmaline i is ; peculiar in containing 5 to 9 p. c. 
of boron. 


_B. CALCAREOUS, OR CARBONATES, SULPHATES, AND PHOS- 
PHATES OF LIME. 


-Caleite, dolomite, aragonite, gypsum, anhydrite, apatite.—Aragonite is 
a large constituent of common uncrystalline limestones, for this form 
of calcium. carbonate enters into the constitution of many shells and 
some other organic secretions, out of which limestones have to a great 
extent been made. Apatite, or calcium phosphate, occurs in beds and 
veins in large cr ystallizations ; but is of especial interest petrologically 
because distributed spar ingly in ae crystals through most 
igneous and metamorphic rocks. 


C. IRoN OXIDES AND SULPHIDES. 


Hematite, magnetite, menaccanite, pyrite, pyrrhotite, marcasite. —The 
oxides constitute beds ; in microscopic grains all are very common in 
basic igneous rocks and i in many metamorphic rocks. 


436 DESCRIPTIONS OF ROCKS. 


Of the above-named silicates the prominent constituents 
of the common rocks include about twenty. ‘These are: 
orthoclase, microcline, oligoclase, andesine, labradoriie, 
anorthite, muscovite, biotite, hydrous micas; nephelite 
(the massive form of which is called cl@olite), leucite ; horn- 
blende, pyroxene (augite), hypersthene ; chrysolite, serpen- 
tine, and two or three species of chlorite. 

a. Arrangement of the enwmerated species according to 
the proportion of silica, or the acidic constituent, in the 
mineral. | 

1. The eminently acidic species. Orthoclase (having 
about 65 p. c. of silica), albite (about 67), oligoclase (about 
60), spodumene (about 64), talc (about 62). 

2. Sub-acidie species. Andesine (about 58 p. c.), leu- 
cite (about 56), dipyre among scapolites (about 56), glau- 
cophane (55-58). 

3. Basic species. Labradorite (mostly 50-54 p. c.), 
anorthite (about 44), nephelite (about 44), most scapolite 
with meionite (40-47), the micas (mostly 40 to 49), gie- 
seckite (45-48) ; saussurites (40-50), zoisite (mostly 40-42) ; 
hornblende of black and dark colors (mostly 40-50, but the 
light green and white var., 55-60), arfvedsonite (49-51), 
pyroxene of black or dark colors (mostly 44-52, diallage 
49-52, but light green and whitish pyroxene 52-56) ; hy- 
persthene (50-53, but enstatite 54-57), sgirite (50-52, but 
acmite 51-55) ; serpentine (mostly 41-43 p. c.). 

4, Ultra-basie species. Sodalite (with hatiynite about 
37 p.c.), epidote (mostly 36-38), zircon (32-34), garnet 
(34-40), chrysolite (mostly 36-40, but fayalite 29-30), 
tourmaline (mostly 36-40), andalusite (36-40), fibrolite 
36-40), cyanite (386-40), topaz (mostly 33-35), staurolite 

about 80), chlorite (mostly 25-34), chloritoid (ottrelite) 
23-27 p. ¢.). | 

b. The distinction of acidic and basic is one easily used 
in the subdivision of rocks, but it is not necessarily that of 
greatest value as regards the nature and origin of rocks, 
That connected with the kind of base is in many cases more 
fundamental, and its use in conjunction with the former is 
to some extent required. ‘The two influential groups in 
this respect are: the al/aline, characterized by the presence 
of potash and soda; and the ferr?/erous, having much iron 
and little or no alkali; the former low in specific gravity 
(mostly under 2°75), the latter high (over 2:75). Using 


DISTINCTIONS AMONG ROCKS. 437 


this characteristic, sodalite and nephelite-may have a place 
with the potash and soda feldspars, where they belong; 
and the micas also, because of their potash. 

The acidic character of a rock is enhanced by the pres- 
ence of quartz (free silica). But the amount of quartz 
which may occur in any quartz-bearing rock varies from 
very little to much; and the same mineral constitution 
often occurs without quartz. Thus syenyte (hornblende 
and orthoclase), dioryte (hornblende and oligoclase), fel- 
syte (orthoclase), trachyte (orthoclase), amphibolyte (horn- 
blende), granite (orthoclase and mica), gabbro and diabase 
(augite and labradorite), etc., occur with and without 
quartz. Quartz is thrown about freely among eruptive 
as well as metamorphic and fragmental rocks, and its pres- 
ence or not is a characteristic therefore of inferior value, 
although of geological interest. It is absent from augitic 
rocks more commonly than from hornblendic. 

ce. The paramorphic relations of certain of the mincral 
species, explained on page 61, have an important bearing 
- on the relations and origin of some rocks. ‘The difference 
in crystallization in paramorphs—‘or example, in pyroxene 
and hornblende—is an unstable difference, one of the two 
species lapsing readily, under certain conditions, into the 
other. Through paramorphism, therefore, two rocks may 
be different mineralogically while identical chemically, and 
by easy alteration become identical mineralogically. 

__ The cases of paramorphism of greatest importance petro- 

logically are the following: that of pyroxene and horn- 
blende, of hypersthene and hornblende, and of aragonite and 
calcite; and, besides these, there are that of andalusite and 
eyanite, of ¢tridymite and quartz, of opal and quartz, of 
glass and stone.- The name of the least stable species in 
each case is here italicized. Further remarks on the altera- 
tions are made and illustrated beyond. 


II. DISTINCTIONS AMONG ROCKS. 
1. Based on General Methods of Origin. 


The first and most obvious division among rocks is 
into (1) Unerystalline and (2) Crystalline. | 

Uncrystalline rocks are made of the fragments of older 
rocks—that is, out of the sand, mud, clay, gravel, derived. 


438 DESCRIPTIONS OF ROCKS. 


from them through disintegration and decomposition; and 
they represent, but in a consolidated form, the sand-beds, 
gravel-beds, and mud-deposits of past time. They include 
also the limestones, which were made from the ground 
shells, corals, etc., of the same eras. They are therefore 
called Fray gmental rocks; or, using a corresponding word 
adopted from the Greek (Alastos, broken), Clastic rocks. 
Crystalline rocks are made not of worn or broken grains 
like fragmental rocks, but of crystalline, as in marble and 
granite. There are three divisions of them: (1) igneous or 
eruptive, or those rocks which came up melted from depths 
below through fissures or through volcanic vents; (2) meta- 
morphic rocks, or those that were made by metamorphism 
out of common limestones, common fragmental rocks, or out 
of older crystalline rocks ; (8) chemically deposited, made by 
deposition from solution, like travertine (p. 236) from cal- 
careous waters, and like the siliceous deposits from, the 
geyser waters of Iceland, or of Yellowstone Park, ete. 
Among eruptive and metamorphic crystalline rocks other 
distinctions are used, as follows. | 


2. Based on Mineral Constitution. 


This is the criterion of chief importance. If a rock con- 


sists of two or more minerals, the two most characteristic — 


are usually taken as the essential constituents, and the 
others are regarded as qualifying minerals distinguishing 
varieties, or else as accessor y Species. Quartz, because of 


its so universal distribution among rocks, is one of the less . 


important ingredients, as observed above; it is the basis 
of quartz-bearing and quartzless kinds under most of the 
eruptive and metamorphic rocks. 


In granite (consisting of quartz, feldspar, aad Beh 


with its schistose variety, gneiss, the most strongly pro- 
nounced characteristic proceeds from the two potash-bear- 
ing constituents; it is the chief potash-bearing rock in the 
world’s foundations. The second marked feature of gran- 
ite is the ‘‘ acidic” quality of the feldspar, orthoclase. The 
quartz serves only to heighten the acidic quality of the 
rock: it may be absent altogether, without affecting essen- 
tially its chemical or minefal nature. So it is in felsyte, 
syenyte, which are also among the acidic rocks: the quartz 


is the less essential and varying ingredient. Quartz occurs 


SS a 


DISTINCTIONS AMONG ROCKS. 439 


occasionally among some basic labradorite rocks, but they 
are nevertheless basic rocks. 


3. Based on Variations in Crystalline Condition or 
Texture. 

The distinctions based on crystalline condition or texture 
speak strongly to the eye, and were formerly deemed of 
prominent importance. 

a. Foliated or not.—This distinction has reference to the 
species hornblende and pyroxene. ‘The foliated variety in 
each (called smaragdite in the former and diallage in the 
latter) has no chemical and small mineralogical impor- 
tance, and recently it has been proved by Judd that it is 
usually a result of slight or incipient alteration. 

°b. Fine-grained or not.—The rocks granulyte, quartz- 
felsyte, and rhyolyte have essentially the same mineral 
composition, but differ in texture; and so also trachyte 
and the felsyte that is free from quartz; dioryte and an- 
_ desyte ; quartz-dioryte and dacyte; gabbro, diabase, doler- 
yte, and basalt. The use of different names in such cases 
is often convenient, but the fundamental identity should 
not be overlooked. Degree of fineness or coarseness has 
depended chiefly on rate of cooling, the finer kinds result- 
ing from relatively rapid cooling. The eruptive rock fill- 
ing a large fissure, or a space opened between layers of a 
stratified rock, is often aphanitic in its outer portion, 
where it was rapidly cooled against cold walls, while coarse- 
grained within, where cooling was very slow. The same 
igneous mass has been found to be scoriaceous and apha- 
nitic exteriorly, while granite-like inside, with gradations 
between: as in Nevada, where the Sutro tunnel gives a 
complete section four miles long (Hague & Iddings, 1885) ; 
in Ireland, where the rock of the same mass varies from 
euphotide having a granitoid texture in part, through 
diabase and doleryte to scoriaceous basalt and basalt-glass 
(J. W. Judd, 1885); in Italy, where other examples occur 
of the same transition from coarse and compact euphotide 
to basalt and basaltic glass (B. Lotti, 1886). 

The cellules and scoriaceous character of an eruptive 
rock are due to the expansive action of suddenly produced 
vapor: the vapor usually of water; but sometimes of car- 
bonic acid, or other vaporizable material. It is absent, 
therefore, at depths below, where the pressure was too great: 


440 DESCRIPTIONS OF ROCKS. 


to allow of vaporization. The cavities of an amygdaloid are 
similar in origin to those of a scoria. In the trap of the 
Connecticut valley these cavities are sometimes cylindrical, 
the diameter not greater than that of a pipe-stem, while 
two or three inches long; they were made (the author 
deems probable) by the sudden vaporization of minute 
drops of liquid carbonic acid. — ; 

c. Porphyritic or not.—When a constituent mineral is 
in defined crystals, and especially when that mineral is a 
feldspar, the rock is said to be porphyritic (Figs. 1 to 3). 
The grouwnd-mass or base may be either fine or coarse in 
texture. The porphyry of the ancients has an aphanitic 
eround-mass, with thickly sprinkled feldspar crystals of 
lighter color. Fig. 1 represents the red antique porphyry 
of Egypt—now called J’osso antico—the rock which gave 
the name porphyry to geology, a kind much used by the 


4. 2 S. be. 

y yy) by Wl yy y , C/T AT 
2 0 // We 

: Yip 33 HB 4 

YW) Hs Ly) / Y 










d 















Py, Ug i; 
Wy Wwe, A | 
i Eye) 
WALLA 


{ 
7s 
Ghia 


4 
uray 





Yi, iy Want 
le Hp fh? Yj Wy} WU) PA U5 
Rosso Antico. Oriental Verd-antique. Porphyritic gneiss. 


Romans (though not by the Greeks or Egyptians), and 
quarried by them in the mountain Djebel-Dokhan, twenty- 
five miles from the Red Sea, in latitude 27° 20’. Figure 2 
is from a polished piece of green antique porphyry from 
western Greece. ‘The feldspar crystals are comparatively 
large, and the compact base has a dark green color. 
Figure 3 represents a large crystal of orthoclase in gneiss, 
from a porphyritie qneiss. The feldspar crystals in porphy- 
ritic gneiss or granite are sometimes over three inches long. 


DISTINCTIONS AMONG ROCKS. 44] 


The orthoclase crystal in porphyritic rocks is often a Carls- 
bad twin (p. 301), the plane of cleavage of one half making 
an angle of 52° 23’ with that of the other half (Vig. 3). 

Rocks are also said to be porphyritic when they contain 
augite (pyroxene), or quartz, or some other mineral dis- 
seminated through the mass in defined crystals; and the 
terms orthophyre, augitophyre, quartzophyre, and others 
similar in form, have thus originated. As various kinds of 
rocks may thus be orthophyres, etc., precision in describ- 
ing them is obtained by making the word an adjective, and 
indicating, in each case, the kind of niineral that is por- 
phyritically defined: thus, augitophyric, when the mineral is 
augite; guartzophyric, when quartz; chrysophyric, when 
chrysolite ; leucitophyric, when leucite; orthophyric, when 
orthoclase; oligophyric, when oligoclase; labradophyric, 
when labradorite; anorthophyric, when anorthite; and 
so on. 

Porphyritic rocks are often treated in petrology as if porphyry were 
a distinct kind of rock, or as if the porphyritic variety of a kind of 
‘rock merited special prominence. But, as recognized beyond, ‘ fel- 
syte-porphyry” is porphyritic felsyte ; ‘* dioryte-porphyry” is porphy- 
ritic dicryte, ‘* diabase-porphyry” is porphyritic diabase; and, in these 
and other like cases, the being porphyritic is a characteristic of minor 
value. On the other hand, a guartz porphyry, as the term has been 
used, is not, consistently with the other kinds, porphyritic quartzyte; 
but, inconsistently. almost any rock except quartzyte, which contains 
disseminated quartz in defined crystals or grains ; the name is doubly 
objectionable because, besides the above inconsistency, it covers rocks 


. 


of various mineral constitution. : 


d. Glass and Stone; Microlites.—Besides the distinction 
of coarse and fine in texture among eruptive rocks, there is 
also that of glass and stone. All stages in the gradation 
from stone to glass exist, and few modern igneous rocks, 
and not all of the ancient, however stony they may appear 
to the eye, are wholly stone, or holocrystalline, as they are 
then termed (from the Greek holos, all, and crystalline). 
Glass is stony material that has been somewhat rapidly 
cooled from fusion ; it is most common in connection with 
orthoclase lavas. A granite may be turned into glass by 
melting, and, if it has little quartz and no mica, into clear 
glass; and bottle-glass has been made out of some kinds of 
trap. Conversely, any glass, if subjected in a furnace to a 
bright red heat (short of the heat of fusion) for three or 
four weeks will pass more or less completely to the lithoid 


442. DESCRIPTIONS OF ROCKS.: 


or stony state—that is, become devitrified, or converted into 
stone. Part of the molecular difference of stone and glass 
is manifested in the inferior specific gravity of the latter. 
Thus in the case of— | aes 


As Stone. As Glass. As Stone. As Glass, 


OAT EZ a ates + G.= 2°65. ..2:19 Augite..... G.=3°27 2°80 
Orthoclase. .. 2°58 2-81 Chrysolite. . o38 818 © 
Labradorite., 2°73 2°57 Doleryte... 2°95 ~ 2°84 
Hornblende.. 3°21 2°82 Trachyte... 2°58 2°45 


The names pitchstone and pearlstone are applied to some 
of the intermediate stages between stone and glass; and 
the name obsidian, to volcanic glass of trachytic or rhyolitic 
outflows ; ¢achylite, to that of basaltic. Figures 4, 5 (from 
Zirkel), and 6 (from Rosenbusch) represent, much-magni- 
fied, transparent slices from glassy rocks in three of their 
stages; Fig. 4 of obsidian, containing radiating clusters 
of hair-like mcrolites (or microscopic minerals), called 
trichites (from the Greek thriz, hair), such as are common 
in all obsidians; Fig. 5, of pearlyte, a light-gray rock of 





Trichites in Ob- 
sidian. 





pearly lustre from the Nevada Basin, having its trichite 
clusters very numerous, and arranged in lines or planes, 
and some of the trichites powdered with pellucid grains, 
or globulites, which are incipient crystals; Fig. 6, of pitch- 
stone, from Weissenberg, in which the microlites are dis- 
tinctly crystalline in form, and some give evidence that 


DISTINCTIONS AMONG ROCKS. A43 


‘they are feldspar crystals, others that they are augite and 
magnetite, and indicate that the rock is intermediate be- 
tween.a glass and a basalt. ‘Thus there is a passage toward 
ordinary stone.. The slags of furnaces are of the nature of 
an obsidian or a tachylite, or of some of the stages between 
it and stone; and they often illustrate igneous rocks in 
their microlitic and mineral structure. Figure 7 repre- 
sents a section much enlarged of a slag found in the soil 
over which a stack of wheat-straw had been burned. The 
crystals No. 1 are melilite; 2, the mineral tridymite, 
(which occurs in cavities in the obsidians of the Yellow- 
stone Park); 3, indeterminate acicular microlites; and 4, 
air-vesicles. Figure 8 is the same from a limekiln slag in 
France; and its minerals and aspect are those of a section 
of doleryte or basalt (as the author of the article, M. Ch. 
Vélain, observes): 1 being magnetite, 2 augite, and 3 
labradorite in lath-shaped crystals. The cavities (4) in 
the latter are described as often coated with acicular crys- 
tals. | 





Slag from the burning of a Slag from a limekiln, basalt- 
stack of wheat-straw. like in composition. 


_ Eruptive rocks, when looking as if stone throughout, 
often have glassy particles among the stony. If they have 
come up through a fissure, the part near. the walls of the 


444 ‘DESCRIPTIONS OF ROCKS. ~ 


fissure may contain particles of glass, and the interior of 
the mass none. Many igneous rocks have glassy grains 
among the stony grains, or a glassy base, because the cool- 
ing was not slow enough for complete lapidification. Such 

9. portions of a rock are described as wnin- 

ic aes, dividualized. An unindividualized base 
- exists in the basalt of Truckee Valley, 
the character of a slice from which, 
highly magnified, is given in Fig. 9 (from 
 Zirkel) ; here, feldspar crystals, of their 
N usual lath-like forms (part of them sani- 
es din), a largish crystal- of chrysolite, and 
ea smaller irregularly shaped augites, are 






3@ extremely small globulite grains that are 
globules of devitrified glass or incipient. 
‘ crystals. The glassy unindividualized 


not of great geological importance. It is, however, the 
chief characteristic separating rhyolyte (quartz-trachyte) 
from quartz-felsyte, trachyte from quartzless felsyte, basalt 
from diabase, andesyte from dioryte, ete. | 

e. Fluidal or not.—Eruptive rocks in thin slices under 
the microscope often exhibit wavy lines or bands, which 


10 Az 








Rhyolyte; Fluidal texture. Broken Crystal. 


are evidence of movement, or flowing, when in the liquid 
state. One variety of this texture, in a Nevada rhyolyte, 
is represented in Fig. 10 (from Zirkel); and another in 
Fig. 5, on page 442. A somewhat similar appearance occurs 


DISTINCTIONS AMONG ROCKS. 445 


at times in fine sedimentary beds, due to flow of the waters 
during their deposition. Broken crystals, also, are often 
evidence of movement of some kind in an igneous rock ; it 
may be that from contraction on cooling, as well as that of 
flow before solidification. Jig. 11 shows an example from 
a microscopic section of a labradorite rock (the bands are 
those developed by polarized light in a triclinic feldspar). 

Fluidal lines and texture have been produced also in 
solid crystalline rocks by powerful movement of one mass 
of rock on another along with, at times, some metamorphic 
change, and they may be evidence oi such movement. 

f. Spherophyric or not.—In consolidation from fusion, 
especially when the fused material is in the state of glass, 
there is often a tendency to segregation around centres, 
and thus to the production of spherulites or globular con- 
cretions. Spherulites have generally a radiated structure ; 
but other concretions consist often of concentric layers. Ob- 
sidian and pearlstone are very often ‘‘spherulitic,” and some- 
times full of large as well as small concentric concretions, 
either kind consisting of orthoclase with some quartz; and 
concretions of different constitution occur in other kinds 
of igneous rocks, and sometimes also in metamorphic rocks. 
The character distinguishes only varieties. ‘the term sphe- 
rophyrie (similar to those describing a porphyritic struc- 
ture, p. 441) is applied beyond to the variety under any 
erystalline rock which has a spherulitic or concretionary 
structure. ‘The structure is different from concretionary 
by deposition around centres, such as is exemplified in 06- 
litic and pisolitic limestone and in clay-stones. Amagdules 
differ from either in that they are made by deposition in 
small vapor-made cavities similar to those of a cellular 
lava. 


4, Based on Supposed Distinctions in Age. 


Small differences in the texture of igneous rocks have 
been regarded as sufficient for an offhand distinction of a 
kind of rock into an earlier and a later section, and for the 
introduction of separate names for the two. Such names 
as earlier diabase and later diabase, earlier dioryte and 
later dioryte, earlier felsyte and later felsyte, the earlier 
including (or thought to) the part older than the Tertiary 
era of geology, have been used; and also the name diabase 
has been restricted to the earlier, and doleryte or basalt used 


- 


A46 DESCRIPTIONS OF ROCKS. 


for the later, masses of a single kind of rock. Since all 
grades of texture, from granite- -like (granitoid) to scoriace- 
ous and glassy, may occur in the same mass of igneous rock, 
whether of Tertiary age or older, the distinction has not 
the value formerly supposed. 

The same principle holds true as regards most metamor- 
phic rocks. The common minerals of these rocks—the 
feldspars, micas, and chlorites—belong to no particular age. 

The only common minerals of metamorphic rocks that 
are now supposed to be confined to the Archezan—eruptive 
rocks excluded—are the accessory species, chondrodite, 
phlogopite, zircon, nephelite, the scapolites; and other 
common species that are much more abundant in Archean 
metamorphic rocks than in later are apatite, augite, horn- 
blende, chrysolite, graphite, titanite, corundum, menacca- 
nite, hematite, magnetite; while those less abundant in 
Archean than in later metamorphic rocks are micas, chlo- 
rites, and the accessory minerals, garnet, staur olite, fibrolite, 
cyanite, andalusite, and tourmaline. 

As to rocks: hornblendic and augitic gneisses and gran- 
ites, syenyte, quartz-syenyte, zircon-syenyte, coarsely 
crystalline dioryte, and other granitoid hornblendic or 
augitic rocks, with epidote and nephelite rocks, prevail most 
among the metamorphic rocks of Archean time. 


5. The Distinction of Lruptive and Metamorphic. 


Many crystalline rocks occur of both eruptive and meta- 
morphic or igin, Some examples of this among the massive 
rocks are granite, syenyte, felsyte, dioryte, gabbro, doleryte 

or diabase. There are also others among schistose rocks ; 
for a schistose structure is now known to be a possible result 
of pressure during, or subsequent to, the cooling of an 
eruptive rock, as wellas during the formation of a meta- 
morphic rock. Further: in the alteration of an augitic 
rock to a hornblendic, a hornblende schist is sometimes 
produced, Massive structure is hence no certain evidence 
of eruptive origin; and neither is schistose of metamorphic, 
although generally indicating it. Hence any attempt to 
divide off crystalline rocks into eruptive and metamorphic 
is necessarily unsatisfactory. Among rocks, only the fol- 
lowing are believed by most petrologists to be tnvarzably 
metamorphic: quartzyte, mica schist, hydromica schist, 


INVESTIGATION OF ROCKS. 447 


chlorite schist, talcose schist, argillyte or phyllyte, serpen- 
tine; and until recently serpentine and even quartzyte had 
been placed among eruptives. 


Ill. INVESTIGATION OF ROCKS. 


The constituents of a rock are usually in a granular state, 
and the ordinary methods of determining their mineral 
nature are often insufficient. When so coarse that they can 
be studied with an ordinary pocket-lens, the texture and 
the methods of study are said to be macroscopic (the prefix 
macro being from the Greek makros, large); and when too 
finely granular for this method of study, the term micro- 
scopic 1s used. 

The macroscopic study of rocks is essentially that of 
ordinary mineralogy, while the microscopic requires that 
transparent sections of the rock should be made for micro- 
scopic examination with ordinary and polarized light, and 
by other means. 

1. Thin Sections.—To make the sections: first take a 
thin chip from ths rock, 4 to # inch across, and grind it to 
a smooth surface on a revolving iron plate, fed with fine 
emery (No. 70) and water. Next secure the chip by the 
flat surface toa piece of glass by means of a little Canada 
balsam, and grind the opposite side in a similar way, and 
continue the grinding until the section is quite thin; after 
which use finer emery and greater care, in order to reach 
the requisite thinness and transparency without breaking 
or wholly wasting the specimen. ‘The Canada balsam used 
is first heated on the glass until the volatile part is driven 
off, but not until it is made brittle if cooled; and air- 
bubbles are carefully excluded in attaching the piece of 
rock to it.. The section thus made is then mounted by 
transferring it to the middle of a glass slide (for which a 
conyenient size is 50 mm. long and 28 mm. wide), made 
ready with balsam; and, with this end in view, the glass 
used in the grinding is first heated to soften the balsam, 
and then the section is pushed from it with a knife-blade 
on to the prepared slide. Before the transfer, a thin cover 
of glass is put over the section with a little balsam; the 
transfer is thus facilitated. Air-bubbles are scrupulously 
guarded against; and if found in the prepared slide, the 
mounting has to be repeated. 


448 DESCRIPTIONS OF ROCKS, 


2. Distinctive Non-optical Characters Investigated.— 
The slicing makes thin sections of all the crystals and grains 
present. Consequently, the forms of such sections of 
crystals are studied. Equilateral forms are looked for in 
isometric crystals; squaro and rhombic forms in octahedrons; 
square and 6-sided in cubes; 6-sided and 4-sided, and others, 
in dodecahedrons (of garnet, etc.); 6- and 8-sided in trape- 
zohedrons; square and rectangular and 8-sided in tetragonal 
crystals; rectangular, rhombic, and 6-sided in orthorhombic 
and monoclinic; and rhombic and scalene forms in the 
case of triclinic species. But it is to be noted that, besides 
these, other forms will occur under each of the systems of 
crystallization, arising from oblique sections in different 
directions, and from the frequent distorted forms of crys- 
tals. Further, when the section is one at right angles to 
the vertical axis it has the interfacial angle of the prism. 

Again, cleavage lines are often distinct, and among them 
some will be pretty sure to have between them the cleavage 
angle of the species: for example, the 124° and 56° of 
hornblends, or 87° 5’ and 92° 55’ of pyroxene, ete.; and 
they may indicate the direction of the 
vertical axis in a prismatic crystalline 
form. The grains may indicate the 
species also by the character of the in- 
tersecting cracks, and other features. 

The microscopic objects inside of 
crystals are of special interest. ‘These 
inclosures may be habitual in a mineral; 
they may be arranged symmetrically or. 
concentrically, as in leucite (Fig. 12), 
or in parallel planes, so as to indicate 
the crystalline form, if not the species. 

The inclosure may be a globule of air alone, and remain 
fixed as the slide is changed in position; or a liquid may 
partly fill it, and the air-bubble move as the position of 
the slide is changed. The liquid may be water, or a kind 
of mineral oil, or carbonic acid (Fig. 13), liquids that differ 
in boiling-points, and so admit of identification if the mi- 
croscope has attachments for the purpose. If it is car- 
bonic acid (CO,), the air-bubble will disappear at a tem- 
perature of 86°-95° F. Liquid CO, requires a pressure of 
384 atmospheres at 32° I’. to keep it liquid, and it there- 





Leucite. 


INVESTIGATION OF ROCKS. 449 


fore occurs encased only in hard and firm minerals, like 
quartz and topaz. ‘The liquid may contain crystals, as, for 
example, a cube of salt (Fig. 14) (showing that it is 
probably salt water), or other kinds of crystals. Some of 
the microlites of an igneous rock are figured on page 442. 
Other investigations are made on the section, while it is 





Liquid Carbonic CubeofSaltinasolu- Magnetitein grouped 
acid; c, air-bubble. tion of the same. crystals, 


upon the stage of the microscope, by means of acids (see 
p. 92, and beyond), to test the presence of lime, soda, sul- 
phur, iron, phosphorus, titanium, fluorine, carbonic acid 
in carbonates, as to the gelatinizing or not of the silica 
resent. A series of reactions made with hydrofluoric acid 
as been worked out by Boricky, and may be found 


17. 





< = 





Garnet crystal with a Chrysolite altered in part 
border of chlorite. to serpentine. 


described in works on Petrography. The fusibility may in 
some cases be tried, and other effects of heat, when pro- 
vided with proper attachments for the purpose. 


450 DESCRIPTIONS OF ROCKS. 


The tendency to oxidation or other alteration in some 
minerals has often produced a clouded or discolored margin 
in certain kinds of grains, that serve as a distinguishing 
character ; iron-bearing minerals, as hornblende, augite, 
garnet, magnetite, etc., often having a rusty margin from 
iron-oxidation, or a green chlorite-like margin from change 
to a chlorite (Fig. 16); and chrysolite grains or crystals 
have often, along irregular intersecting fracture-lines, 
serpentinous and rusty material and magnetite (Fig. 17). 

Incipient alteration produces also at times, especially in 
pyroxene and hypersthene, a peculiar lustre arising from 
minute points of materials developed within, and the pro- 
cess has been named (by J. W. Judd), from the name 
schiller spar (or its German origin), schillerization ; and, 
accompanying this, there is a tendency in pyroxene to be- 
come laminated, or to pass to a diallage. 

3. Optical Characters Investigated.—The methods of 
optical investigation are briefly described on pages 70-80. 
With thin sections, observations are made to ascertain the 
existence of pleochroism or not in colored minerals, and its 
characters when existing; whether, with crossed nicols, 
there is a change from dark to light, or not, as the section 
on the stage is revolved; for if not, the substance is amor- 
phous, like glass, or isometric, or, it may be, an air-vesicle; 
whether the optical characteristics are those of uniaxial or 
biaxial crystallization, or of circular polarization as in 
quartz; what the position of the plane of the optic axes; 
whether extinction is parallel or inclined; and what the 
angle of extinction if inclined; whether there is a twinned 
or compound structure, a simple twinning or polysynthetic; 
and so on. ‘The twinning and cleavage lines often aid in 
determining the direction of the vertical axis, and thus in 
orientating the object (giving it its normal position). 

4, Other points investigated.—Besides the study of min- 
eral distinctions, there is the microscopic study of mineral 
changes and the kinds and origin of transformation in 
rocks. 

The changes studied include also (1) methods of consolida- 
tion; (2) crystallization; (3) paramorphic transformations ; 
(4) chemical transformations; (5) mechanical movements. 

a. In consolidation.—The consolidation sometimes de- 
velops crystalline forms. In the case of a siliceous sand- 
stone there are ordinarily additions to the exterior of the 


INVESTIGATION OF ROCKS. 451 


original grains, turning them into crystals of quartz. Grains 
of a quartz sandstone are always parts of quartz crystals 
having crystallographic axes; and 
the material added in the consoli- 
dation is added in subordination to 
these axes, as shown first by Térne- 
bohm and Sorby. It is illustrated 
in Fig. 18, an enlarged view of one 
of the grains of the Potsdam sand- 
stone of New Lisbon, Wisconsin 
(A. A. Young). In this way sand- 
beds have become an aggregation 
of minute crystals, although gener- 
ally failing of this because of the 
filling of the interstices. The 
same happens with grains of feld- 
spar and hornblende (Irving, Van Hise). 

b. In paramorphic changes.—TYhe paramorphic change 
of pyroxene to hornblende is well 19 
traced out under the microscope. 
The figure (from Hawes) represents 
a crystal of augite changed to horn- 
blende except over a central portion, 
as the cleavage angles in the two 
parts show. The change is not 
always a paramorphic change alone, 
for there is often some loss and 
gain of ingredients attending the 
change, the pyroxene often losing tb , 
in lime and gaining in magnesia, Pyroxene changed to 
This kind of change has great geo- | Hornblende (Uralite). 
logical importance, since it is now known that many horn- 
blende rocks, supposed to be eruptive, have been thus made; 
and that many hornblendic Archean rocks have had the 
same kind of origin. Hypersthene undergoes a similar 
transformation. 








The change of pyroxene to hornblende, first noticed by Rese in 
1831, was regarded, until recent years, as only a local occurrence. 
But ten years since, in November of 1876, Mr. 8. Allpert described 
the ‘‘ dolerytes” of Land’s End as more or less altered to hornblende 
rocks, reporting that some portions had become ‘‘ half-formed horn- 
blende-schist;” and his paper gives examples of the same from half a 
dozen other English localities. The change was recognized also by 


452 DESCRIPTIONS OF ROCKS. 


Streng and Wichmann in 1876, and afterward by Pumpelly, Irving, 
and Wadsworth, among the ‘‘ greenstones” and other eruptive rocks 
of Michigan and Wisconsin. In 1878, G. W. Hawes pointed out, in 
his report on the rocks of N. Hampshire (Geol. N. H., iii 205), the 
derivation, through the same kind of change, of a hornblende-syenyte 
from ‘‘ augite-syenyte” of three N. Hampshire localities, one on 
Little Ascutney Mountain. In 1883, Irving and Van Hise announced 
that the hornblende gneisses, granites, and syenytes of the Wisconsin 
Archean had been derived from augitic gneisses, granites, and syenytes; 
and G. H. Williams further illustrated this subject in 1884. In 1886 
Van Hise showed that mica had been made from feldspar. 


The change in the aragonite of a limestone to calcite 
takes place at the time of crystallization, and this may be 
either before or during the time of metamorphism; and 
that to dolomite takes place probably at the time of original 
consolidation of the calcareous sands, the half-evaporated 
waters of a sea-border marsh affording the magnesia. 

Another example of a paramorphic change is that of the 
mineral andalusite (G. = 3°1) to cyanite (G. =3°56). The 
tendency to the change is strong, andalusite crystals often 
being altered within. In its incipient stage the interior 
has often the structure represented much magnified in Fig. 


20. ; 21. 





20, and in the later, that in Fig. 21 (both from Hawes), in 
which the andalusite prism is made up of small prismatic 
forms of cyanite. 

ce. In chemical changes.—Some of the chemical changes 
that are microscopically studied are those of chrysolite and 
other minerals to serpentine (p. 330); of augite to hyper- 
sthene or enstatite; of augite (with some aid from feldspar) 
to chlorite or to epidote; of hornblende similarly to chlorite 
or epidote or biotite; of garnet to chlorite; of orthoclase to 
mica; of menaccanite to leucoxene; of magnetite to limon- 
ite; and of the beclouding of the feldspars and their change 
to saussurite, or to chlorite, etc. 


INVESTIGATION OF ROCKS. 453 


In these chemical changes some ingredients are usually 
set free; and these are often left in part within the space of 
the original mineral, arranged concentrically along its lines 
of cleavage, or in its rifts, or scattered about outside. The 
iron discharged takes the form of magnetite, or hematite, 
menaccanite, picotite, or chromite, or sometimes native 
iron. 

Fig. 22 (from Hawes) shows the magnetite as it occurs 





Partially altered Chrysolite. 


often in altered hornblende, and also biotite (centre of fig- 
ure) and calcite (lath-shaped grains), which are likewise 
products of the alteration. The magnetite is a common 
product in the change of chrysolite to serpentine (Fig. 23, 
from Judd), representing (enlarged 
100 diameters) partially altered 
chrysolite with the products of de- 
composition along the rifts. Lime 
is often discharged in augitic and 
hornblendic alterations, and if CO, 
is present, calcite is formed, as in 
Fig. 22. Silica is also often set 
free; and liquid globules of the CO,, 
if present, often become enclosed 
in the crystallizing quartz. Men-  /- 
accanite (titanic iron) changes to @ ieycoxene from Menac- 
grayish white or whitish material canite. 

called lewcoxene (see p. 312), which 

has often a reticulated appearance (Fig. 24, from Hawes) 
owing to the progress of the change along cleavage lines or 
rifts. 





~ 


454 DESCRIPTIONS OF ROCKS. 


Such changes are very different from the oxidations due 
to surface weathering, which are another subject of study. 


For a large part of the chemicai changes carried on ‘hroughout the 
mass of the rock, (1) the presence of moisture was required, many of the 
minerals formed, as serpentine, chlorite, zeolites, etc., being hydrous; 
(2) also the presence of carbonic acid, calcite being a very common 
product; (3) also, for some of the changes, other vaporizable ingredients, 
including metallic compounds or vapors. The introduction of the 
vapors into the rock and their general diffusion could have taken 
place only when the rock was melted, and therefore only while it was 
rising from the depths below. The liquid rock, at a temperature be- 
tween 1500 and 2500 F., should it pass, in the ascent, rocks containing 
some moisture (0°6 p. c. would be a pint to a cubic foot, capable of 
yielding nearly 30 cubic feet of vapor at the ordinary pressure), or en- 
counter subterranean streams (whose waters might be saline or mineral), 
vapors in great volume would be sure to form and be forced to enter the 
upward-moving rock (without upward movement in the liquid rock they 
could not enter or take the form of vapor); or, if passing a limestone 
stratum, CO2 would escape and be carried up; and so for other vaporiz- 
able materials. ‘The hot vapors would be active agents among the 
constituent minerals, and, as the right temperature was reached, would 
begin destructive and reconstructive work, and carry it on with such 
new results as the declining temperature favored. And thus has prob- 
ably come many of the changes that have gone on throughout the 
interior of rocks, producing from the original mincrals the chlorite, so 
common, the serpentine, saussurite, the quartz in crystallized and 
chaleedonic forms, zeolites, and also copper ores, silver ores, etc. 
The aluminium-sodium carbonate, called dawsonite, was one of the 
products in a dike of felsyte intersecting limestone near Montreal. 


In the changes where vapors are concerned, the first 
effect is usually an incipient beclouding of the feldspars 
and of the other silicates; but when carried forward by heat 
without or with but a feeble supply of moisture, as'appears © 
to have been the fact in many examples of the paramorphic 
kind, the feldspars may remain unaltered. 

Some volcanic glass, when highly heated, loses much vol- 
atile matter (moisture ?), and is converted into pumice; a 
dacite-glass lost 8:9 per cent. (J. W. Judd.) 


IV. MICROSCOPIC CHARACTERS OF COMMON ROCK 
CONSTITUENTS. 


1. Isometric or Amorphous. 


Glass.—Optical characters of an amorphous substance (p. 70). 

Opal.—Outlines not angular; no cleavage-lines. Often concentric 
in structure. Sometimes interference colors, due to internal strains. 
In diatoms and sponge-spicules, no colors. 


MICROSCOPIC CHARACTERS. 455 


Leucite.—Outlines 8-sided. Uncolored. Often containing concen- 
tric or radiating series of microlites (Fig. 1, page 448) or glass. Often 
feeble double refraction with polysynthetic twinning bands, crossing 
at 90° or 45°. 

Garnet.—Outlines 6-, 8-, and 4-sided, or irregular. Pale red disk 
to brown and nearly colorless; irregularly fractured. Sometimes 
changed at the margin or throughout to chlorite (Fig. 16, p. 449); often 
contains grains of quartz or other inclusions. 

Magnetite.—Squares, rhombs, or hexagonal outlines, often in den- 
dritic groups. Opaque. 

Pyrite.—Outlines, squares, and other isometric figures. Opaque. 
Brass-yellow by reflected light. 


2. Tetragonal and Hexagonal. 


Quartz.— Outlines sometimes sections of quartz crystals, but usually 
irregular. No cleavage lines. Field never wholly dark on the rotation 
of anicol. In oblique or vertical sections interference colors brilliant; 
in basal sections, if they are not too thin, the characters of circular 
polarization. By reflected light the quartz grains in a section of whitish 
granite appear darker than the feldspar grains. Often contain glo- 
bules of COz. 

Tridymite.— Hexagonal tables (p. 262 and 448). Interference colors 
not brilliant. Polarization not circular, but crystals usually too thin 
to use this distinction. 

Nephelite.—Often hexagons and rectangles. Colorless. Gelatin- 
izes; reactions for soda (p. 92). Inclosures common, and often hex- 
agonally arranged. 

Tourmaline.—3-, 6-, and 9-sided outlines. No vertical cleavage 
lines; never finely fibrous. Strongly dichroic. 

Scapolite.—Squares, rectangles, 8-sided sections. Few vertical 
cleavage lines, some transverse. Interference colors brilliant; no 
dichroism. 

Zircon.—Squares, etc.; always in crystals; no cleavage lines. Not 
distinctly dichroic. Interf. colors brilliant. 

Apatite.—Hexagons, long rectangles, needles; cleavage not much 
distinct. Often having dust-like enclosures. Reactions for lime and 
phosphorus. 

Hematite.— Hexagonal and irregular outlines. Blood-red to orange 
in very thin slices. 

Menaccanite (Ilmenite).—Similar to 205. 
hematite, but black and opaque instead of 
blood-red in thin slices. Often a grayish 
white border and intersecting lines owing 
to the production of leucoxene by altera- 
tion (p. 453). Reaction for titanium. 

Calcite, Dolomite.—Grains generally 
polysynthetically twinned (Fig. 25), the 
bands parallel to the longer diagonal. In- 
terference colors feeble. 

Spherulites also give in polarized light ee 
the black cross of a uniaxial substance, FR OOS 
owing to the radiated structure; the cross |S SSS 
revolves with the revolution of the plate. Crystalline Calcite. 





456 DESCRIPTIONS OF ROCKS. 


8. Orthorhombic. 


Enstatite.—Prismatic, often fibrous. Extinction parallel to vert. 
axis,»or cleavage-lines. Interference colors very brilliant. Not di- 
chroic. | 

Hypersthene (Amblystegite included).—Like enstatite, but dichroic, 
yet feebly so unless containing much iron. Usually cleavage parallei 
to the brachypinacoid. Inclusions parallel to this plane often give a 
metalloidal lustre. More decomposable than pyroxene, being often 
altered when the pyroxene (as seen in a thin slice) is fresh. 

Chrysolite (Olivine).—Not prismatic in habit, nor fibrous. No 
regular cleavage lines, but irregular rifts, along which usually altered 
to greenish, grayish, and brownish, or rusty; or changed wholly to 
serpentine (p. ), and then often containing grains of magnetite, 
chromite, or picotite. Not dichroic. Interf. colors brilliant. 

Staurolite.—Rhombic or 6-sided outlines, and crossed forms through 
twinning; in transverse section rhombic angle 128°. Cleavage lines 
not very distinct. Interf. colors brilliant. In small clear crystals 
strongly dichroic. Very numerous enclosures, especially grains of 

uartz. 
Fibrolite (Sillimanite).—Long prismatic to fibrous; longitudinal 
cleavage-lines. Extinction parallel to prismatic lines. Interf. colors 
brilliant. Not dichroic. No tendency to alteration like that of andal- 
usite. 

Andalusite.—Prismatic, not fibrous; basal sections nearly square. 
Crystals usually altered, imperfectly polarizing, containing minute 
slender secondary crystals, and sometimes, through alteration, having 
the characters of cyanite. Chiastolite variety has a regular arrange- 
ment of impurities, which are partly carbonaceous, this being indi- 
cated by the loss B.B. of the color. 

Zoisite.—Six-sided and other sections; not finely fibrous. Cleavage- 
lines in only one direction, parallel to vertical axis. Interf. colors 
usually little brilliant. Not dichroic. 


4, Monoclinic. 


Orthoclase.—Never columnar or fibrous; cleavage-lines parallel to 
clinodiagonal. Twinning never polysynthetic. Optic-axial plane in 
the clinode section. Extinction angle measured with axis ¢ (or verti- 
cal), 21° 7’. Interf. colors rather brilliant, but less so than in quartz, 
anc if section is very thin, of blue-gray color and faint. 

Hornblende.—Sections acute rhombs and hexagons. Prismatic, 
often fibrous and granular; in transverse sections cleavage lines usually 
distinct in two directions, the angle 124° 30’, but in vertical sections 
only vertical lines. Optic-axial plane in the clinode section. Extinc- 
tion angle (with axis c) usually 15°, varying between 2° and 18°. 
Strongly pleochroic; usually alternating green and yellow through a 
basal section on rotation of the lower nicol, and bluish through a pris- 
fae section; interference colors not very bright with the black horn- 
blendes. 

Pyroxene.—Prismatic and granular; in transverse sections, 4- 
and 8-sided outlines, with cleavage lines in two directions, the angle 
87° 5’. Optic-axial plane in clinode section; extinction angle (with 


DESCRIPTIONS OF ROCKS. 45% 


axis ¢) usually 39° (varying to 54°), the angle on the opposite side of ¢ 
from that in hornblende. Feebly or not dichroic. 

Muscovite.—Hexagons and triangles in basal sections, but oblique 
sections lined in one direction from edges of cleavage-lamine. Ex- 
tinction parallel, as in orthorhombic species. Rather feebly dichroic. 
Optic-axial angle very large, and the plane of the axes macrode. For 
biotite, the same, but optic-angle very small to 0° (p. 291), and strongly 
dichroic. 

Meroxene.—Similar to biotite, but optic-axial plane brachode. 

Epidote.—Sometimes columnar, not very fine fibrous. Cleavage 
lines in one direction, the orthode. Optic-axial plane clinode. Ex- 
tinction angle (on ¢c) 2° 29’. Interf. colors brilliant. Strongly pleo- 
chroic. 


5. Triclinic. 


Albite and other Triclinic Feldspars.—Cleavage as in ortho- 
clase; the crystals of fine-grained rocks commonly tabular, parallel to 
vertical section through axis a@ (clinode section in orthoclase), and 
hence showing lath-like forms (Fig. 9, p. 444) in thin slices, and 
usually having the longer side in the direction of the vertical axis (c). 
Generally polysynthetic twinning in such sections lengthwise (not ap- 
parent in sections transverse), and showing usually two or more bands 
of color unless too thin for more than one. Extinction angle, meas- 
ured on the edge O/7-, varying for the species: Albite, 3° 54’-4° 51’; 
microcline, 15°; oligoclase, 2°-4°; labradorite, 5°—7°; anorthite, 27°-387°. 

Cyanite (Kyanite).— Prismatic vertically and flattened parallel to 
7-7 (or to section through c); cleavage-lines in the prismatic direction. 
Extinction angle, in sections parallel to 7-2, on cleavage-lines or cor- 
responding edge, 30°, but very thin sections required for the trial. 


VI. DESCRIPTIONS OF ROCKS. 


The grander subdivisions of rocks here adopted are three 
in number : 

1. CALCAREOUS Rocks or LIMESTONES. 

2. FRAGMENTAL ROCKS, NOT CALCAREOUS. 

3. CRYSTALLINE Rocks, EXCLUSIVE OF THE CALCARE- 
OUS. 

In the names of rocks, the termination ze is here changed to yte, as 


done in the author’s ‘‘ System of Mineralogy” (1868), in order to dis- 
tinguish them from the names of minerals. Granite is excepted. 


I. Calcareous Rocks or Limestones, 


1. UNCRYSTALLINE. 


1. Massive Limestone.—Compact. Colors dull gray, blu- 
ish gray, brownish, and black, sometimes yellowish white, 
cream-colored, nearly white, red of different shades. ‘Tex- 


458 DESCRIPTIONS OF ROCKS. 


ture varying from earthy to compact semi-crystalline. 
Hardness about 3, and hence easily scratched with the 
point of a knife. G. = 2°25-2-%5. 

In constitution ordinary massive limestone varies be- 
tween a calcium carbonate or non-magnesian limestone, 
and a calcium-magnesium carbonate or magnesian lime- 
stone. ‘The two kinds are undistinguishable by the eye 
alone ; and they are alike also in losing the carbonic acid 
when heated B.B. (or in a limekiln), and by the action of 
acids, as already explained. The non-magnesian may con- 
sist of calcite, or of calcite with much aragonite, since 
shells and other organic calcareous secretions are often 
largely aragonite. Magnesian limestone—since it has 
originated from calcareous sediment by a chemical change 
through magnesian waters (probably sea-marsh brines)—is 
less likely to contain aragonite ; it may be true dolomite in 
composition (p. 238), but it is generally a mixture of dolo- 
mite and calcite. 


VARIETIES.—The varietics are alike under the above kinds. They 
differ in texture, color, presence of fossils or impurities, and in other 
qualities. Among them are the following: a. Compact. Db. 
Lamellar. c. Earth, y, of which chalk is a white calcite variety. d. 
Oolitic, consisting of minutely concretionary grains. e. Pésolitic, con- 
sisting of concretions as lar geas peas. f. Bird's-eye, having scattered 
crystalline points, asin a limestone of western New York. g. Con- 
glomerate, a calcareous pudding-stone. h. Fosstliferous, consisting 
chiefly of fossils. i. Coral or Madreporic, containing or consisting of 
fossil corals. j. Encrinal or Crinotdal, containing disks of crinoids. 
k. Nummulitic, consisting of disk-shaped fossils called nummulites. 
1. Cherty, containing siliceous nodules or layers. ; 

The above kinds may be of various colors. The gray and black 
colors are commonly due to carbonaceous material; for they burn 
white; but the yellow and red usually to the presence of the yellow or 
red iron-oxide. 

A black marble, much used in Eastern U. S., comes from Shoreham, 
Vermont, and other places near L. Champlain, and near Plattsburg 
and Glenn’s Falls, N. Y.; also from Isle La Motte. A pudding-stone 
marble, of various dull shades of color, from the banks of the Poto- 
mac, in Maryland, 50 or 60 miles above Washington, is the material 
of columns in the interior of the Capitol at Washington. 

The Portor is a Genoese marble highly esteemed ; it is deep black, 
with veinings of yeilow; the most beautiful is from Porto-Venese. 
The Nero-antico is an ancient deep black marble; the Paragone, a 
modern one, of fine black color, from Bergamo; and Panno di morte, 
another black marble with a few white fossil shells. 

A beautiful marble from Sienna, Brocatelio di Siena, has a yellow 
color, with large irregular spots and veins of bluish red or purplish. 


DESCRIPTIONS OF ROCKS. 459 


The Mandelato is light red, with yellowish white spots. The Madre- 
poric marble is the Pietra stellaria of the Italians. 

Some of the pyramids of Egypt, including the largest, the pyramid 
of Cheops, is made of nwmmuilitie limestone ; and this is the building 
material of Aleppo, the range of mountains between Aleppo and An- 
tioch being composed largely of this cream-colored rock. 

A soft Tertiary limestone occurring in the vicinity of Paris has 
afforded a vast amount of rock, of an agreeable pale yellowish color, 
for fine buildings in Paris ; and a similar rock has long been used in 
Marseilles, Montpellier, Bordeaux, Brussels, and other places in 
Western Europe. The shell-rock, or Coguina, of St. Augustine, in 
Florida, is an aggregate of shell fragments or shell sand. 

Etre-marble, or Lumachelle, isa dark brown shell marble, having 
within brilliant fire-like or chatoyant reflections, 

Ruin marble is a yellowish marble, with brownish shadings or lines 
arranged so as to represent castles, towers, or cities in ruins. These 
markings proceed from infiltrated iron. Itis an indurated calcareous 
marl, and does not occur in large slabs. 

Lithographic stone is a compact limestone, very fine and even in tex- 
ture, and of light gray and yellowish color, affording a very even 
surface good for use in lithography. 

Hydraulic limestone (Cement stone, in part) is a gray impure 
limestone, the quicklime from which makes a mortar that will 
set under water. It is often a magnesian limestone. The impur- 
ity is the source of its hydraulic character, and amounts in the 
best to 20 to 30 per cent. by weight of the rock; it is clayey or 
feldspathic material, consisting chiefly of silica and alumina in 
combination with free silica. The hydraulic limestone (mag- 
nesian) of Rondout, N. Y., afforded on analysis—besides lime, 
magnesia, and carbon dioxide—silica 15°37, alumina 9°13, iron 
sesquioxide 2°25. In making ordinary mortar, sand (quartz) is 
mixed with the quicklime and water, and a hydrate of calcium is 
formed, with much evolution of heat; the hardening requires, fur- 
ther, the drying away of the water; and then CO:, of the atmosphere, 
becomes combined after a while with the lime. With ‘‘ hydraulic 
cement” the elements of the clayey impurity, distributed in a fine state 
through the lime, enter into combination with it, and hardening goes 
on while water is present; and thus it “‘sets’” under water. An arti- 
ficial hydraulic cement is made in England, by mixing 70 p. c. of 
chalk with 80 p. ce. of the all::vial clay or mud within the lower tidal 
basins of the Thames and the Medway—the mud supplying the silica 
and alumina in the proper condition; and this makes the so-called 
Portland cement. 

Carbonaceous Oil-bearing Limestones.—A kind used for building in 
Chicago, of the Niagara period, becomes spotted or streaked with 
blackish mineral oil, after a few years’ exposure to the weather. 
Much mineral oil and gas are obtained by boring into the Trenton 
limestone in northwestern Ohio. 

Much of the common limestone of the United States is magnesian. 
That of St. Croix, Wisconsin, the ‘‘ Lower Magnesian,” afforded 
Owen 42°43 per cent. of magnesium carbonate. 

In some limestones the fossils are magnesian, while the rock is com- 


460 DESCRIPTIONS OF ROCKS. 


mon limestone. Thus, an Orthoceras, in the Trenton limestone of 
Bytown, Canada (which is not magnesian), afforded T. 8. Hunt, Cal- 
cium carbonate 56°00, magnesium carbonate 37°80, iron carbonate 5°95 
= 99°75. The pale yellow veins in the Italian black marble, called 
‘‘Beyptian marble” and “‘portor” (see above), are dolomite, accord- 
ing to Hunt; and a limestone at Dudswell, Canada, is similar. 


2. Marl.—A clayey or earthy deposit containing a large 
proportion of calcium carbonate—sometimes 40 to 50 per 
cent. Ifthe marl consists largely of shells or fragments 
of shells, it is called Shell-marl. 

3. Travertine—A massive limestone (calcium carbon- 
ate), formed by deposition from calcareous springs or 
streams (see p. 236). It is usually cellular, and more or less 
concretionary. A handsome compact banded kind, trans- 
lucent, and of great beauty, comes from Tecali, about 35 m. 
from the city of Mexico. 

Stalagmite has a similar origin. 


2. CRYSTALLINE LIMESTONE. 


Granular or Crystalline Limestone. (Marble.)—Lime- 
stone having a crystalline-granular texture, white to gray 
color, but sometimes of reddish and other tints from im- 
purities. It is in most cases, if not all, a metamorphic rock, 
and was originally common limestone. 

Like common limestone, it may be either— 

I, Calcyte, calcium carbonate, more or less pure. 

II. Dolomyte, calctum-magnesium carbonate. 

Ill. Calcitic Dolomyte, a mixture of calcite and dolomite, 
much more common as a rock than pure dolomite. It 
contains no aragonite, the crystallization undergone chang- 
ing this mineral to calcite. 

The impurities are often mica, tremolite, white or gray 
pyroxene, scapolite, pyrite ; sometimes serpentine, through 
combination with which it passes into ophiolyte; occasion- 
ally tale, chondrodite, phlogopite, apatite, corundum, chlor- 
ite, spinel, graphite, etc. ‘Talc, tremolite, pyroxene, chlor- 
i a0 serpentine are common, especially in the dolomitic 

inds, 


VARIETIES.—a. Statuary marble ; pure white and fine-grained. b. 
Decorative and Architectural marble ; coarse or fine, white, and mot- 
tled of various colors, and, when good, free not only from iron in the 
form of pyrite, but also from iron or manganese in the state of car- 


DESCRIPTIONS OF ROCKS. 461 


bonate with the calcium, and also from all accessory minerals, even 
those not liable to alteration, and especially those of greater hardness 
than the marble which would interfere with the polishing. Calcitic 
dolomyte often weathers to calcareous sand, owing to a loss of its cal- 
cite (the more soluble ingredient) by infiltrating waters. 

c. Verd-antique, or Ophiotyte, containing serpentine. d. Micaceous. 
e. Tremolitic; contains bladed crystallizations of tremolite.  f. 
Canaanite ; contains white pyroxene ina massive form. g. Graphitic ; 
contains graphite in disseminated scales. h. Chloritic; contains 
chlorite. i. Chondroditic ; contains disseminated chondrodite in large 
or small yellow to brown grains. 

White and grayish white marble is abundant in western New Eng- 
land and southeastern New York (Westchester Co.). The texture is 
less coarsely crystalline in Vermont than in Massachusetts. Fine cal- 
cyte marbles are quarried in Dorset, West Rutland, Pittsford, and 
other places in Vermont, and statuary marble occurs in Pittsford. 
In Vermont, the best quarries occur where the strata stand at a high 
angle: the layers were subjected to great pressure in the upturning 
that gave them this position, and this pressure has soldered many 
layers together that are separate where the pressure was less; conse- 
quently blocks as large as an ordinary house might be obtained at 
some quarries. Fine marble (dolomyte) is quarried at Lee, Mass, 
Valuable marble exists also in Pennsylvania, Maryland, and Tennes- 
see. The mottled reddish brown dolomyte from East Tennessee, and 
mainly from Knox and Hawkins counties, is a beautiful marble ; it is 
a Lower Silurian rock, and although semi-metamorphic, contains 
Cheetetes and other fossils. Another handsome marble is the mottled 
red of Burlington, Vt., from the semi-crystalline Winooski dolomyte 
limestone ; and a still finer the deeper red (or cherry red), mottled and 
veined with white, of Swanton, Vt., from the same limestone on the 
northern borders of the State, both of the Cambrian, and sometimes 
containing fossils. 

The Carrara marble of Italy, the Parian, of the island of Paros 
(the birthplace of Phidias and Praxiteles), and the Pentelican, from 
quarries near Athens, Greece, are examples of crystalline calcyte lime- 
stone. The Carrara marble varies in quality from coarse to true 
statuary marble, and the best comes from Monte Crestola and Monte 
Sagro. The Cipolin marbles of Italy are white, or nearly so, with 
shadings or zones of green talc. 

Excellent quicklime is made of crystalline limestone, whether it be 
calcyte or dolomyte. Fora good product perfect freedom from im- 
bedded minerals is essential. It does not afford hydraulic lime, as a 
trial at New Haven, Ct., with an impure feebly crystalline limestone 
of right chemicai constitution, proved ; the impurity in that case was 
in the state of mica. 


IJ. Fragmental Rocks, exclusive of Limestones. 


1, Conglomerate—A rock made up of sand and pebbles, 
or angular fragments of rocks of any kind; ordinarily made 
by the consolidation of a gravel-bed. (a) If the pebbles 


462 DESCRIPTIONS OF ROCKS. 


are rounded, the conglomerate is a pudding-stone; (b) if 
angular, a breccia. 


VARIETIES.—a. Stliceous or quartzose. b. Granitic. c. Caleareous. 
d. Pumiccous. e. Basaltic. 


2. Grit—A hard, siliceous conglomerate, called also 
millstone grit, because used sometimes for millstones. 

3. Sandstone——A rock made from sand, or by the con- 
solidation of a sand-bed. 


VARIETIES.—a. Siliceous or Quartzose ; consisting chiefly of quartz. 
b. Granitic; made of granitic material or comminuted granite. 
c. Micaceous ; containing much mica. d. Argillaceous; containing 
much clay with the sand. e. Gritty ; hard, and containing small 
quartz pebbles. f. Herruginous ; containing iron-oxide, and therefore 
having a red or yellowish brown color. g. Concretionary ; made up 
of concretions. h. Laminated ,; consisting of thin layers or lamine, 
or breaking into thin slabs, a characteristic most prominent in argil- 
laceous sandstones. i. Friable ; crumbling in the fingers. j. Hossilif- 
erous ; containing fossils. k. Heldspathie (Arkose) consisting of 
quartz and feldspar, the latter in coarsish, cleavable grains ; arkose 
includes also a feldspathic quartzyte. 

The paving-stone extensively used in New York and the neighbor- 
ing States is a laminated sandstone, of the upper part of the Hamilton 
group in geology, quarried just south of Kingston, and at many other 
places on the west side of the Hudson River. The rock is remarkable 
for its very even laminaticn. In western New York and in Ohio, the 
Devonian sandstones, above the Hamilton group, together with the 
Waverly group, afford a similar flag-stone. The ‘‘ brown-stone” used 
much in New York and elsewhere for buildings is a dark-red sand- 
stone from the Triassic formation, and is from Portland, Conn., on 
the Connecticut River, opposite Middletown, where it has been 
quarried since the middle of the 17th century. A lighter-colored 
‘‘brown-stone” or ‘‘ free-stone,” of the same age, also much used for 
buildings, comes from Newark, Belleville, Little Falls, and other 
points in Central New Jersey. The handsome sandstone of light 
olive-green tint, much employed in architecture, is from the Lower 
Carboniferous group in New Brunswick. The soft white sandstone, 
in much esteem among architects because so easily cut and carved, 
comes from Ohio quarries, in beds of the Carboniferous; it is mostly 
from a bed about sixty feet thick, called the ‘‘ Berea grit,” and is 
obtained at Berea and Independence in Cuyahoga County, and Am- 
herst in Lorain County, and elsewhere. 

Pyrite is often present in sandstones used for building, and has de- 
faced and is Bes ty Ine many a beautiful structure by its oxidation, 
and the consequent decay of the rock. 

Sandstoncs absorb moisture most easily in the direction of the bed- 
ding or grain, if there is any distinct bedding; and hence the blocks, 
when used for a building or wall, should be placed with the bedding 
horizontal. It is, further, the position in which the stone will stand 
the greatest pressure. . 


DESCRIPTIONS OF ROCKS.> 463 


Grindstones are made from an even-grained, rather friable sand- 
stone, and are of different degrees of fineness, according to the work 
to be done by them; were it not friable enough to yieid in the grind- 
ing, the stone would become polished by the worn metal. Scythestones 
are of similar nature, but finer. 

Hard siliceous sandstones and conglomerates, occurring in regions 
of metamorphic rocks, are called ‘‘ granular quartz,” or quartzyte 
(p. 468). 

A rock made of sand, especially when not of siliceous material, is 
often calledasand-rock. A calcareous sand-rock is made of calcareous 
sand; it may be pulverized corals or shells, such as forms and consti- 
tutes the beaches on shores off which living corals and shells are 
abundant. 


4, Shale—aA soft, fragile, argillaceous rock, having an 
uneven, slaty structure. Shales are of gray, brown, black, 
dull greenish, purplish, reddish, and other shades. It may 
consist of clay and fine sand, or contain much finely pul- 
verized feldspar. It is fine mud consolidated. Often 
called slate, as the slates of the coal-formation. 


VARI@TIES.—a. Ordinary, of different colors. b. Bituminous shale, 
or Carbonaceous shale (Brandschiefer of the Germans), impregnated 
with coaly material and yielding mineral oil, or gas, or related bitum- 
inous matters when heated. c. Alwm shale ; impregnated with alum 
or pyrites, usually a crumbling rock; the alum proceeds from the 
alteration of pyrite or the allied iron sulphides (p. 191-192). Shale 
graduates into laminated sandstone. 


5. Argillyte, or Phyllyte (Roofing slate, Writing slate) — 
Argillaceous, slaty, differing from shale in breaking usually 
into thin and even slates or slabs; sometimes thick-lami- 
nated. Often graduates into hydromica and _ chloritic 
schists, and also, on the other hand, into shale. Often 
called Clay-slate. Much slate is hydromica schist ; some 
is fine hornblendic and epidotic schist. 


VARIETIES.—a. Bluish black. b. Tile-red. c. Purplish. d. Grayish. 
e. Greenish. {. Ferruginous. g. Pyritiferous. lh. Thick-laminated ; 
affording thick slabs, instead of slates. i. Staurolitic. j. Ottrelitic. 
k. Hornblendic ; microscopally so. 1. Thack-bedded and often arena- 
ceous (Graywacke); a massive rock, affording thick blocks or masses. 

Extensive quarries of slate exist in Vermont at Waterford, Thet- 
ford, and Guilford, in the eastern slate range of the State; in North- 
field in the central range, and in Castleton and clsewhere in the 
western range. There are excellent quarries also in Maine and 
Pennsylvania. The rock furnishes also thick slabs for various eco- 
nomical purposes. <A trial as to water absorption, and a close ex- 
amination as to the presence of pyrite, is required before deciding 
that a slate rock is fit for use, however even its fissile structure. 


464 DESCRIPTIONS OF ROCKS. 


Kinds with a glossy surface are most likely to be impervious to moist- 
ure, but they may be too brittle for good slate. 
Catlinite ; red clayey pipestone; Minnesota. 


6. Tufa—A sand-rock, conglomerate, or shale, made fron 
comminuted volcanic or other igneous rocks, more or less 
altered. Colors yellowish brown, gray, brown, sometimes 
red. Usually loose-textured. Common in volcanic regions. 
The name, from the Italian ¢wfo, is often written in Kng- 
lish ¢u ff. 


VARIETIES.—a. Trachytic ; made of trachyte, of an ash-gray color, 
or of other light shades. b. Andesytic ; made of andesyte. c. Pumi- 
ceous ; made of fragments of pumice. d. Basaltic; made from 
basic igneous rocks, such as doleryte (trap) or basalt; usually yellow- 
ish brown or brown in color, sometimes red. Pozzuolana is a light- 
colored tufa, found in Italy, near Rome, and elsewhere; it is used 
for making hydraulic cement. Wacke is earthy, brownish, like an 
earthy trap or doleryte, usually made of trappean or dolerytic material 
and compacted into a soft rock. 

Much of the ‘‘sandstone” and some shales of the Tertiary in the 
Rocky Mountain region (Montana, Idaho, Colorado, Arizona, etc.) 
are tufa (mostly andesytic or trachytic); and petrified trees and opal 
have been formed in it, as explained on p. 259. Tufas, or “ash- 
beds,” occur among the Paleozoic and later beds of Great Britain. 


7. Sand. Gravel—sSand is comminuted rock-material ; 
but common sand is usually comminuted quartz, or quartz 
and feldspar, while gravel is the same mixed with pebbles | 
and stones. Sand often contains grains of magnetite, or 
of garnet, or of other hard minerals existing in the rocks of 
the region. Occasionally magnetite or garnet is the chief 
constituent, especially in the upper portions of some sea- » 
beaches. 

Volcanic sand, or Peperino, is sand of volcanic origin, 
either the ‘‘ cinders” or ‘‘ ashes” (comminuted lava), thrown 
upward from the crater of a volcano, or lava rocks other- 
wise comminuted. 

8. Green Sand.—An olive-green sand-rock, friable, or not 
much compacted, consisting of grains of glauconite, with 
more or less sand. See p. 329. 

9. Clay.—Soft, impalpable, more or less plastic material, 
chiefly aluminous (kaolinite) in composition, white, gray, 
yellow, red to brown in color, and sometimes black. Made 
chiefly from orthoclase feldspar, by decomposition. Often 
contains much quartz sand, and, if alkali-bearing, pulver- 
ized feldspar. See Kaolinite, p. 3382. 


DESCRIPTIONS OF ROCKS. 465 


VARIETIES.—a. Kaolin, purest unctuous clay. b. Potter’s clay, 
plastic, free from iron ; mostly unctuous ; usually containing some 
free silica. Pipe-clay is ‘similar, c. Fire-brick clay, the same; it may 
contain much sand without injury, as sand is needed with the clay 
for brick-making. d. Lerruginous, ordinary brick clay, containing 
iron in the state of oxide or carbonate, and consequently burning 
red, as in making red brick. e. Containing tron tn the state of silt- 
cate (?), and then failing to turn red on being burnt, as the clay of 
which the Milwaukee brick are made. f. Adkaline ‘and vitrifiable, 
containing 2°5 to 5 per cent. of potash, or potash and soda, owing to 
the presence of undecomposed feldspar, and then not refractory enough 
for pottery or fire-brick. g. Marly, containing some calcium car- 
bonate or ground shells. h. Weak clay, containing too much sand 
for brick-making. i. Alwm-bearing, containing aluminous sulphates, 
owing to the decomposition of iron sulphides present, and hence used 
for making alum. 


10. Alluvium. Silt. Till—Adlwviwm isthe earthy deposit 
made by running streams or lakes, especially during times 
of flood. It constitutes the flats either side of a stream, 
and is usually in thin layers, varying in fineness or coarse- 
ness, being the result of successive depositions. 

Silt is the same material deposited in bays and harbors, 

where it forms the muddy bottoms and shores. 

Less is a fine earthy deposit, following the courses of 
valleys or streams, like alluvium, but mostly without di- 
vision into thin layers. Usually contains some calcareous 
material in concretions. Occurs in elevated terraces, along 
the broad parts of large valleys, as the Rhine, Danube, 
the Hoangho in China, and on some parts of the Mississippi. 

Trill is the unstratified sand, gravel, and stones, with more 
or less clay, deposited by glaciers; called also wnstratified 
drift. 

Detritus (from the Latin for worn) is a general term 
applied to earth, sand, alluvium, silt, gravel, because the 
material is derived, to a great extent, from the wear of 
rocks through disintegrating agencies, mutual attrition in 
running water, and other methods. 

Soil is a mixture of clay, quartz, sand, and other tritu- 
rated rock material, along with carbonaceous matters from 
vegetable and animal decomposition, and from the last gets 
its dark color and also a chief part of its fertility. 

11. Tripolyte (Infusorial Harth).—Resembles clay or 
chalk in appearance, but is a little harsh between the 
fingers, and scratches glass when rubbed on it; also occurs 
firm and slaty from partial consolidation. Consists chiefly 

30 


466 DESCRIPTIONS OF ROCKS. 


of siliceous shells of Diatoms with often the spicules of 
sponges, and is silica in the opal state. Forms thick 
deposits, and is often found in old swamps beneath the 
peat. 


This soft diatomaceous material is sold in the shops under the 
name of silex, electro-silicon, and polishing powder, and is obtained for 
commerce in Maine, Massachusetts, Nevada, California, ete. A bed 
exceeding fifty fect in thickness occurs near Monterey in California ; 
and other large beds in Nevada near Virginia City, and elsewhere. 
It is used as a polishing powder; in the manufacture of ‘‘ soluble 
glass ;’ and, formerly, mixed with nitro-glycerine to make dynamite. 
Occurs slaty at Bilin, Prussia; 2elso hard or indurated in some regions, 
from consolidation through infiltrating waters, and thus graduates, at 
times, into chert and opal. 


II. Crystalline Rocks, exclusive of Limestones 


In the review of the constituent minerals of rocks it has 
been shown that orthoclase and mica are closely related in 
composition, both being eminently potash-bearing species, 
and that mica has often been derived from feldspar with 
very little change in the amount of alkali (pp. 287, 438); 
and also that leucite is closely related to the potash feld- 
spars and nephelite to the soda-lime feldspars. It has also 
been observed that hornblende and pyroxene are intimatel 
related, they being alike in chemical constitution; that 
hornblende is readily derivable from pyroxene by paramor- 
phic change (pp. 272, 451), and that it is chemically unlike 
biotite and other micas in the usual absence of an alkali, 
and in other ways. It has further been remarked that — 
rocks are acidic or basic according to the feldspar in their 
constitution, without reference to the presence of quartz; 
and that guartz in grains is distributed widely through 
igneous and metamorphic rocks as it is through sedimen- 
tary, and has relatively little value as a ground of distinc- 
tions among kinds of rocks (p. 438). It has also been shown 
that no satisfactory line can be drawn between the kinds 
of igneous and metamorphic rocks (p. 446). 


From these and other considerations explained, we are 
led to the following arrangement of the crystalline rocks. 


DESCRIPTIONS OF ROCKS. 467 


A. Pate ROCKS, OR THOSE CONSISTING MAINLY 


B. FELDSPAR, MICA, LEUCITE, NEPHELITE, SODALITE, 
OR RELATED ALKALI-BEARING SPECIES, A CHIEF .- 
CONSTITUENT. 


In the subdivisions 1 to 3 a potash-feldspar is a promi- 
nent constituent; in 4 leucite, also a potash-bearing min- 
eral; in 5 and 6 a soda-lime or lime feldspar. 

1, The Potash-Feldspar and Mica Series. Hminently 
alkali-bearing rocks, both the mica, whether muscovite, 
biotite or lepidomelane, and the feldspar, whether ortho- 
clase or microcline, affording on chemical analysis much 
potash, and the feldspars often also some soda. The soda- 
feidspar, albite or oligoclase, is a common accessory in- 
gredient. ‘The series shades off into a rock that is chiefly 
feldspar, and another that is chiefly mica; and in these 
two extremes the amount of potash yielded is about the 
same. The mica sometimes contains 4 or 5 per cent. 2 
water, or is a hydrous species (page 335). 

2. Potash-Feldspar and Hornblende or Pyroxene Series, 
Related to the granite series, but contains the non-alkaline 
mineral hornblende in place of mica, with or without 
quartz. ‘Transitions between the granite and syenyte rocks 
are common—a bed of true mica schist often becoming 
hornblendic, or having alternating micaceous and horn- 
blendic laminew; and so there are similar transitions in 
other parts of the two series. 

3. Potash-Feldspar and Nephelite Rocks, Hornblendic or 
not. 

4. Leucite Rocks, Augitic or not. 

5. Soda-lime-Feldspar and Mica Series. 

6. Soda-lime-Feldspar Series, with or without Hornblende 
or Pyroxene. The feldspar either of the triclinic species, 
from albite to anorthite. 


. SAUSSURITE ROCKS. 


Saussurite and zoisite are alike, as pointed out by Hunt, 
in having high specific gravity (3 and outs and thus unlike 
the feldspar’ and scapolite series to which they are related 
in composition. 


468 DESCRIPTIONS OF ROCKS: 


D. WITHOUT FELDSPAR, OR WITH VERY LITTLE. 
1. Garnet, Epidote, and Tourmaline Rocks. 
2, Hornblende, Pyroxene, and Chrysolite Rocks, 


E. HYDROUS MAGNESIAN AND ALUMINOUS ROCKS. 


A. SILICEOUS ROCKS. 


1. Quartzyte, Granular Quartz.—A siliceons sandstone, 
usually very firm, occurring in regions of metamorphic 
rocks. Does not differ essentially from the harder siliceous 
sandstones of other regions. Conglomerate beds are some- 
times included. Sometimes friable, passing to loose sand; 
and flexible (Jéacolumyte). 


VARIETIES.—a. Massive. b. Schistose. c. Micaceous. d. Hydro- 
micaccous ; it graduating at times into hydromica or mica schist. c. 
Feldspathic, sometimes porphyritic (the rock Arkose); this variety oc- 
curs northeast of Lenox, Mass., near the borders of the towns of 
Lenox and Washington, and also in Pownal and Bennington, Yt.; 
when it loses its feldspar it becomes cellular, like buhrstone, and in 
this state has been used for millstones; by the presence also of mica 
it becomes gneissoid or graduates into gneiss. f. Hriable. g. Flex- 
ible (ttacolumyte) ; the rock occurs in the gold regions of Brazil and 
N. Carolina. h. Andalusitic ; containing andalusite, asin Mt. Kear- 
sarge. i, Zourmalinic ; containing tourmaline. 

In Western New England, in Vermont to the west of the principal 
ridge of the Green Mountains, and in Berkshire Co., Mass., and 
Canaan, Ct., in strata of great thickness, also between Bernardston, 
Mass., and Vernon, Vt.; in the central part of New Hampshire; in the 
Archean area of Wisconsin, and in the Rocky Mountain region. It 
occurs friable, and as sand (used for glass-making), in Cheshire, Savoy, ~ 
and Washington, in Berkshire Co., Mass. 

j. Novaculitic-quartzyte, or Novaculyte (Whetstone). _Novacutyte, in 
part, is an extremely fine grained siliceous rock. Of this nature is 
the variety from Whetstone or Hot Spring Ridge, in Arkansas, This 
ridge, 250 feet in height above the Hot Spring Valley, is made up of 
the beautiful rock, ‘‘ equal,” says D. D. Owen, ‘‘in whiteness, close- 
ness of texture, and subdued waxy lustre, to the most compact forms 
and whitest varieties of Carrara marble. Yet it belongs to the age of 
the millstone grit.”” Dr. Owen supposed it to have received its impal- 
pable fineness through the action of the hot waters on sandstone. An 
analysis of the rock afforded him (Second Rep. Geol. Arkansas, 1860, 
p. 24), Silica 98°0, alumina 0°8, potash 0°6, soda 0°5, moisture, with 
traces of lime, magnesia, and fluorine 0°1 = 100. He states that along 
the southern flank of the ridge there are over forty hot springs, hav- 
ing a temperature of 100° F. to 148° F. Solid masses from the fine 
rock have been got out weighing about 1,200 Ibs. 


DESCRIPTIONS OF ROCKS: 469 


2. Siliceous Slate. (Phthanite.)—Schistose, flinty, not 
distinctly granular in texture. Sometimes micaceous, and 
thus graduates into mica or hydromica schist. 

3. Chert.—An impure flint or hornstone occurring in 
beds or nodules in some stratified rocks. Often resembles 
felsyte, but is infusible. Colors various. Sometimes odlit- 
ic. Kinds containing iron oxide graduate into jasper and 
clay-ironstone; and others, occurring as layers or nodules 
in limestone, are whitish, owing to the limestone material 
they contain. Chert sometimes contains cavities which 
are lined with chalcedony or agate, or with quartz crystals, 
making what are called geodes. 

4, Jasper rock—Dull red, yellow, brown, or greenish 
color, or of some other dark shade, breaking with a smooth 
surface like flint. Consists of quartz, with more or less 
iron oxide as coloring matter; the red contains the oxide 
in an anhydrous state, the yellow in a hydrous; on heating 
the latter it turns red. 

5. Buhrstone.—Cellular siliceous, flint-like in texture. 
Found mostly in connection with Tertiary rocks, and 
formed apparently from the action of siliceous solutions on 
preéxisting fossiliferous beds, the solutions removing the 
fossils and leaving cavities. 

Buhrstone is the material preferred for millstones. The buhrstone 
of the vicinity of Paris, France, has long been largely exported for 


this purpose. Buhrstone is reported from the Tertiary in Greenville 
District, South Carolina, 100 miles up the Savannah River. 


6. Fioryte. (Siliceous Sinter, Pearl Sinter, Geyserite.) 
—Opal-silica, in compact, porous, or concretionary forms, 
often pearly in lustre. Deposited from hot siliceous waters, 
as about geysers (Geyserite), and made in other ways. 


Geyserite is abundant in Yellowstone Park, and about the Iceland 
and New Zealand geysers. See Opal, p. 261. 


B. CONTAIN AS A CHIEF CONSTITUENT EITHER A 
FELDSPAR, MICA, LEUCITE, NEPHELITE, SODA- 
LITE, OR A RELATED ALKALI-BEARING SPECIES, 


I. POTASH-FELDSPAR AND MICA SERIES. 


Besides rocks consisting of orthoclase (or microcline), 
mica, and quartz, others are here included containing but 
two of these ingredients; and also those consisting chiefly 


4°70 DESCRIPTIONS OF ROCKS. 


of orthoclase or of mica, as part of mica schist and much 
hydromica schist. Mica in many such rocks has been 
made from feldspar (p. 452). 

1. Granite.—Orthoclase (or microcline), mica, and quartz; 
massive, with no appearance of layers in the arrangement 
of the mica or other ingredients. G. = 2'5-2°8. The 
quartz usually grayish white or smoky, glassy (and distin- 
guished by absence of cleavage); the feldspar commonly 
whitish or flesh-colored, its cleavage surfaces usually dis- 
tinct and brilliant in the sun-light; the mica in bright 
scales, either whitish (muscovite), or black (biotite, or, at 
times, some more iron-bearing species). Oligoclase or al- 
bite often present, and usually of whiter color than the 
orthoclase. 

Both eruptive and metamorphic. Metamorphic granite 
often graduates into, or alternates with, gneiss. 


Vanrizeties.—A. Muscovite granite; B. Muscovite-and-biotite gran- 
ite, the most common kind; C. Biotite granite (graniiyte); D. Hydromi- 
ca-granite. 

a. Common or Ordinary granite, color grayish or flesh-colored, accord- 
ing as the feldspar is white or reddish, and dark gray when much black 
mica is present. Granite varies in texture from jine and even, to coarse, 
and that of granite veins has often the mica, feldspar, and quartz— 
especially the two former—in large crystalline masses. An average 
granite (mean of 11 analyses of Leinster granitc, by Haughton) affords 
Silica 72°07, alumina 14°81, iron protoxide and sesquioxide 2°52, lime 
1°63, magnesia 0°33, potash 5°11, soda 2°79, water 1°09 = 100°35. __b. 
Porphyritic; orthophyric, and either (@) small porphyritic, or (f) large 
porphyritic, and the base (v) coarse granular, or (6) fine, and even 
subaphanitic. c. Alditic; contains some albite, which is usually white. 
d. Oligoelase granite (Miarolyte); contains much oligoclase. e. Micro- » 
cline granite; contains the potash triclinic feldspar, microcline. f. 
Hornblendic; contains black or greenish black hornblende, along with 
the other constituents of granite. g. Black micaccous,; consists largely 
of mica, with defined crystals of feldspar (porphyritic), and but littie 
quartz. h. Chloritic. i. Zirconitic; containing zircons. j. Lolitic; con- 
taining iolite. k. Spherophyric,; containing concretions consisting 
chiefly of mica (as at Craftsbury, Vt., where it is called pudding-gran- 
ate). 1, Gneissoid,; a granite in which there are traces of stratification; 
graduates into gneiss. m. Micrograniie; having a very fine-grained 
base in which mica exists with feldspar, the latter often in defined 
crystals; when quartzophyric, it is one of the kinds of Quartz-porphyry, 
a kind of rock occurring at the junction of granite and an andalusite- 
hydromica schist on.the west side of Mt. Willard, near Crawford’s, 
White Mountain Notch. For muscovite-granites the name Pegmatyieé 
was used by Naumann, perverting it from its original use. 

The following are prominent regions of granite quarries. In 
Maine: at Hallowell, a whitish granite, sometimes a little gneissoid; at 


DESCRIPTIONS OF ROCKS. AU1 


Rockport, whitish; at Clarke’s Island, spotted gray; at Jonesbury, 
flesh-red; also in the Mt. Desert region. In New Hampshire, at vari- 
rious places, but most prominently near Concord, a fine-grained whitish 
granite. In Massachusetts at several points, especially in Gloucester 
at Rockport, a red granite. (For Quincy “‘ granite” see Syenyte.) In 
Rhode Island, at Westerly, a fine-grained whitish granite. In Con- 
necticut, at Millstone Point, near Niantic, and at Groton, near New 
London, a fine-grained whitish granite; at Stony Creck, a pale reddish 
and cream-colored, but liable to large micaceous spots; at Plymouth, 
on the Naugatuck, a whitish granite, even and fine-grained, more 
easily worked than the Westerly. Aberdeen, Scotland, affords the 
handsome red granite much used for monuments and in architecture; 
also Peterhead, Scotland. 


2. Granulyte. (JMicaless granite, Aplyte, Weiss-stein, 
Pegmaty/e.)—Consists of orthoclase and quartz, with no 
mica or very little; often contains some albite or oligoclase 
and garnets. Coarse to fine-grained. White to flesh-red. 
G. = 2°6-2°7. Silica 70 to 80 p. c. Sometimes schistose. 
Metamorphic or eruptive. 


VARIETIES.—a. Common granulyte; white and usually fine granular; 
occurs in Saxony, Bohemia, Moravia, usually containing small gar- 
nets; also in Western Connecticut and Westchester Co., New York; 
at Rye, N. H., containing very little quartz. b. Wlesh-colored, usually 
coarsely crystalline, granular, and flesh-colored; a coarse flesh-colored 
“‘oranite” of the Eastern or Front Range of the Rocky Mts., in Colo- 
rado; it contains a little albite or oligoclase with the orthoclase. c. 
Garnetiferous. d. Hornblendic; containing a little hornblende—a 
variety that graduates into syenyte. e. Magnetitic; containing dissem- 
inated grains of magnetite, a kind common in Archean regions, in the 
vicinity of the iron-ore beds, occurring in Orange Co., N. Y., and 
south in New Jersey, and also at Brewster’s, Dutchess Co., N. Y., and 
in Kent and Cornwall, Conn. f. Graphic; quartzophyric (Pegmatyte), 
the quartz looking like Persian cuneiform charactcrs over the cleav- 
age surface of coarsely crystallized feldspar. g. Microgranulyte, fine- 
grained, often orthophyric or quartzophyric (making one kind of 
quartz-porphyry, called also idcropegmatyte), found in the Vosges. 

Eruptive granulyte has been shown by Lehman to be sometimes 
schistose as a consequence of pressure. The name pegmatyle was ap- 
plied by Haiiy to graphic granulyte from the Greek pégma, joined 
together, alluding to the quartz in the feldspar. 


3. Gneiss—Like granite in constituents, colors, and 
specific gravity, but the ingredients arranged more or less 
in layers, and hence schistose; varying from feebly schistose, 
or granitoid, to strongly so, the latter easily dividing into 
slabs. Usually metamorphic. 


VARIETIES.—a. Granitoid ; often graduating into granite.  b. 
Strongly schistose and micaceous. c. Muscovite gneiss; not common. 


472 DESCRIPTIONS OF ROCKS. 


d. Muscovite-biotile gneiss. e. Biotite gneiss. f. Albitic. g. Oligo- 
clastic. h. Hornblendic; containing hornblende as well as biotite. 
i. Hpidotic. j. Garnetiferous, k. Andalusitic. 1. Cyanttic. m., Hibro- 
litic; containing fibrolite. n. Quartzose,; containing much quartz. 0. 
Quartzytic, consisting largely of quartz in grains and graduating toward 
quartzyte, as in Berkshire, Mass. p. Porphyritiic; orthophyric, Fig. 3, 
p. 440, porph. gneissof Birmingham, Ct. q. Spherophyvric, containing 
‘ concretions of mica or feldspar and mica. r. Quwartzophyric; contain- 
ing quartz in defined crystals in a fine-grained base, and sometimes 
orthophyric also, a kind of quartz-porphyry called also Porphyroid 
and Hyalophyre, found intercalated among stratified beds in the Ar- 
dennes. 


4. Greisen —Massive, without schistose structure. A 
compact micaceous quartz rock. ‘T'he mica may be mus- 
covite, lepidolite, or biotite. Occurs in regions of gneiss, 
granite, or quartzyte, and sometimes graduates into these 
rocks. Metamorphic. Also called Hyalomicte. 


Occurs in characteristic form at Zinnwald, in the Erzgebirge, where 
it sometimes contains tin cre as an accessory ingredient, and is fre- 
quently penetrated by veins of tin; also in the tin ore regions of 
Schlackenwald and Cornwall. Occurs in the region of quartzyte, 
hornblendic rocks and gneiss, of Upper Silurian or Devonian age, 
between Bernardston, Mass., and Vernon, Vt., within three miles 
northeast of the former placc; and also near Vernon, but at this place 
it contains usually a little hornblende, making it a very tough rock, 
anel is intermediate between the quartzyte, hornblendic rock, and mica 
schist of the region. 


5. Protogine. Protogine-gneiss——Coarse to fine granular, 
granite-like or gneissoid in structure, and mostly the latter; 
grayish white to greenish gray; consists of quartz, white or 
grayish white, rarely flesh-red orthoclase, a dark green mica, 
and often chlorite, with some greenish white hydrous mica 
and white oligoclase. Metamorphic. 


The dark green mica approaches chlorite, as shown by Delesse, in 
its very large percentage of iron oxide (Fe.O; 21°31, FeO 5:03), but it 
gave him only 0°90 of water, with 6:05 of potash. Among accessory 
minerals are hornblende, titanite, garnet, serpentine, magnetite. In 
an analysis of the protogine as a whole, Delesse obtained Silica 74°25, 
alumina 11°58, iron oxide 2°41, lime 1°08, water 0°97, leaving 10°01 
for potash, soda, and magnesia. From the region of Mont Blanc and 
other parts of the Swiss Alps. 

At Littleton, N. H., a granite occurs consisting of orthoclase, chlor- 
ite, and quartz, with a little hornblende; at Lancaster, it is orthophyric; 
at Lebanon, it is a green-spotted rock with some scales of biotite, in- 
dicating that this mineral is the source of the chlorite; at Wallin’s 
quarry, N. H., is an epidotic variety. a 


DESCRIPTIONS OF ROCKS. 43 


6. Minette. Ortholyte. (Mica-syenyte.)—Gray to brown; 
fine-grained, compact, massive. Consists of orthoclase with 
much mica, and a little hornblende, with some apatite and 
magnetite; sometimes porphyritic. Silica 50 to 65 p.c. 
Metamorphic? 

From the Vosges, near Framont, where it occurs in beds; also in 


Saxony. The name Ortholyte is adopted on the geological map of 
France. Approaches kersantyte, which is a plagdoclase-mica rock. 


¢. Mica Schist—Mica, with usually much quartz, some 
feldspar. On account of the mica, usually thin schistose. 
The schist either muscovite schist or biotite schist; the lat- 
ter much the more common; or contains both micas, which 
is the most common. 

Colors silvery to black, according to the mica present; 
often crumbles easily; and road-sides sometimes spangled 
with the scales. ‘The disseminated scales or crystals of 
biotite sometimes set transversely to the bedding. Meta- 
morphic. 


VARIETIES.—a. Ordinary ; coarse or fine, and various in color and 
constitution according to the kind of mica present or most abundant. 
b. Gnetssoid ; between mica schist and gneiss, and containing much 
feldspar, the two rocks shading into one another. c. Hornblendic. 
d. Garnetiferous. e. Staurolitic. f. Oyanitic. g. Andalusitic. h. 
Fibrolitic ; containing fibrolite. i. Tourmalinic. j. Ottrelitic. k. 
Calcareous ; limestone occurring in it in occasional beds or masses, 
1. Graphitic (or Plumbaginous); the graphite being either in scales or 
impregnating gencrally the schist. m. Quartzose ; consisting largely 
of quartz. n. Quarizytic; a quartzyte with much mica, rendering it 
schistose. 

o. Specular schist, or [¢tabyrite; containing much hematite or specu- 
lar iron in bright metallic lamelle or scales. 


8. Hydromica Schist.—Thin schistose, and consisting 
either chiefly of hydrous mica, or of this mica with more or 
less quartz; the surface nearly smooth; feeling greasy to the 
fingers, like talc; pearly to faintly glistening in lustre; 
whitish, grayish, pale greenish, and also of darker shades. 
Metamorphic. 


This rock used to be called talcose slate and magnesian slate, but it 
contains no tale. It includes Parophite schist, Damourite slate and 
Sericite slate (Glanz-Schiefer and Seriecit-Schiefer of the Germans). 
Much argillyte or roofing slate is here included, as first shown by Sorby. 


VARIETIES.—a. Ordinary; more or less silvery in lustre. b. Chlo- 
ritic; contains chlorite, and has sometimes spots’ of olive-green color, 
as in Orange, east of N. Haven, Ct., and in the Taconic Range on the 


AG4. DESCRIPTIONS OF ROCKS. 


western boundary of Massachusetts; graduates into chlorite schist. c. 
Garnetiferous. d. Pyritiferous; contains pyrite in disseminated grains 
or crystals. e. Magnetitic; contains disseminated magnetite. f. Quart- 
eytic; consists largely of quartzyte, which is thus rendered schistose. 

A variety of hydromica schist (but called argillyte), from the White 
Mountain Notch, containing andalusite, afforded Dr. Hawes Silica 
46°01, alumina 30°56, iron sesquioxide 1°44, iron protoxide 6°85, man- 
ganese protoxide 0°10, magnesia 1°42, soda 1°12, potash 6°66, titanium 
dioxide 1°93, water 4°13 = 100°22, which is near the composition of a 
mica. (N. Hampshire Geol. Rep., ii. 233.) Another, from Wood- 
ville, N. H., afforded Hawes Silica 60°49, alumina 19°35, Fe.C; 0°48, 
FeO 5:98, lime 1°08, magnesia 2°89, soda 2°55, potash 3°44, water 
8°66 = 99°92. This slate, as he recognizes, is chemically like granite ; 
but, by the microscopic study of thin slices, he found it to consist of 
mica and quartz, with probably some feldspar and chlorite. The 
close relation in ultimate composition between the extremes of the 
granite series, granite and some argillyte, is here well illustrated. All 
the difference that exists may be due simply to difference in grade 
and conditions of metamorphism. 


9. Agalmatolyte. ((Gieseckite, 1813; Dysintrybite, 1852; 
Pinite in part.)—Aphanitic; cut with a knife; composition 
that of the hydrous mica, damourite. Massive. G. = 2°75- 
2°85. Greenish gray, reddish gray. Derived mostly from 
the alteration of nephelite. From Greenland; China; Nor- 
way; the Archean of Lewis Co., N. Y. (See p. 335.) 

10. Paragonite Schist.—Consists largely of the hydrous 
soda mica called paragonite (p. 290); but in other characters 
much resembling hydromica schist. Metamorphic. 

11. Felsyte. (Huryte, Porphyry, Petrosilex.)—Compact 
orthoclase, mostly aphanitic, with commonly more or less 
quartz intimately mixed; often orthophyric (and called 
Porphyry) ; sometimes quartzophyric (Quartz-porphyry); | 
occasionally spherophyric ( Globular porphyry); occasionally 
schistose. Contains sometimes oligoclase, mica, minute 
apatites, and garnets. Silica 63-81 p. c. Colors white, 
grayish white, red, brownish red, brown, black, G. = 
2°56-2°68. Metamorphic and eruptive. 


VARIETIES.—a. WVon-porphyritic, of various colors. b. Black. 
c. Orthophyric. d. Quartzophyric. e. Quartzless ; colors various. , 
f. Spherophyric ; the Pyromeride of Corsica, Schneeberg, and Regen- 
berg, in which the concretions are large, and consist of orthoclase with 

uartz. 
i A gray porphyritic felsyte occurs in dikes at Albany and Mt. Pleas- 
ant, Groveton and Waterville, N. H.; gray to red about Mt. Pequaw- 
bet. A black with ‘‘ here and there a grain of quartz” at Waterville, 
N. H., affording only 63°63 p. c. of silica, with nearly the constitution 
of orthoclase. A nearly quartzless variety at Chambly, Canada (silica 


DESCRIPTIONS OF ROCKS. 475 


67°60 p. c.). A quartzless felsyte, red, locally at Waterville and. 
Albany, N. H.; also in dikes in Montreal Mtn., containing dawsonite 
(p. 220). Felsyte from Cottonwood Cafion, W. Humboldt Range, 
made metamorphic by King, afforded B. E. Brewster Silica 74°74, 
alumina 14°14, Fe.O; 0°79, lime 1°51, magnesia 0°39, soda 0°92, potash 
5°29, water 1°88 = 99°66, which is the composition of a normal felsyte. 
The antique red porphyry (‘‘rosso antico’’) is a variety of dioryte. 


12. Porcelanyte. (Porcelain Jasper.)—A baked clay, hav- 
ing the fracture of flint, and a gray to red color; B.B. 
somewhat fusible and thus differs from jasper. Formed 
by the baking of clay-beds that contain feldspar. Such 
clay-beds are sometimes baked to a distance of thirty or 
forty rods from a trap dike, and over large surfaces by 
burning coal-beds. Metamorphic. 

13. Mica-Trachyte.—Orthoclase and black mica, with a 
little oligoclase, augite and chrysolite, and glass in the base. 
Texture fine-grained to compact. Color dark grayish 
green. Hruptive. Monte Catini, Italy. 

14. Trachyte. (Sanidin-trachyte.)—Mainly orthoclase, 
with often disseminated glassy tabular crystals of sanidin, 
and thence orthophyric with sanidin; oligoclase often pres- 
ent; glassin the base ; sometimes spherophyric ; often hay- 
ing small needles of hornblende, scales of biotite, magnetite, 
microscopic apatite. Silica 60 to 64 p. c., but less in kinds 
containing much oligoclase or hornblende. G. = 2°6-2°65. 
Owing to the angular forms of the glassy feldspar (sani- 
din) and the porosity, has a rough surface of fracture, 
whence the name from the Greek trachus, rough. Color 
ash-gray, greenish, bluish to brownish gray, rarely reddish. 
G. = 2°6-2°7. Accessory minerals, besides those mentioned, 
augite, nepheline, hatiynite, tridymite. Sometimes augito- 
phyric. Graduates into quartz-trachyte or rhyolyte. Krup- 
tive. 


VARIETIES.—a. Plain trachyte. b. Orthophyric, the sanidin crystals 
small or large. c. Oligoclase-bearing (Domyte), and sometimes oligo- 
phyric. d. Hornblendic under each of the above varieties. e. Spar- 
ingly micaceous, under each. f. Augitic, and sometimes augitophyric, 
graduating toward augite-andesyte. g. Containing pyrope. h. Vesicu- 
lar, passing into a trachytic lava and pumice. 

Common in eruptive regions of Hungary, Italy, and many other 
parts of Europe. <A kind from Ischia afforded Silica 61°49, alumina 
20°02; Fe.O; 3°11, FeO 2°72, MnO 0°01, magnesia 0°52, lime 1°88, 
soda 3°39, potash 7°13, phosphoric acid 0°02, ign. 0°46 = 100°%5. 
The trachyte of the Drachenfels, near Bonn, contains oligoclase, and 
is porphyritic with large crystals of sanidin; contains also some 


46 DESCRIPTIONS OF ROCKS. 


needles of hornblende, a little augite. Oligoclase-trachyte (domite) 
occursalso in the Puy de Dome, the Euganean Hills (Northern Italy), 
the Siebengebirge, Eifel. Not common in western N. America, 
rhyolyte (quartz-trachyte) usually having its place. 


15. Rhyolyte or Quartz-trachyte. (Liparyte.)—Like the 
preceding trachyte in its rough surface of fracture, color, 
and more or less glassy, fluidal base, with frequently sani- 
din crystals; but contains quartz, and is often quartzo- 
phyric ; occasionally spherophyric. Coarsely crystalline to 
fine-grained and glassy; also scoriaceous. Often contains 
some oligoclase, hornblende in needles, black mica; and 
sometimes tridymite and topaz in cavities. G. = 2°33-2°64. 
Colors light to dark gray, reddish, yellow, brown, and 
black. Silica 70 to 82 p. c.; a kind from McKinney’s Pass, 
Nevada, afforded Woodward Silica 74:00, alumina 11°93, 
Fe,0O, 2°48, lime 1°56, soda 2°64, potash 5°65, water 1:24 = 
9503 4a = 2°35. 

Vartieties.—Those of trachyte; with also: h. Coarsely porphyritic, 
and almost granitoid (evadite); i. Quartzophyric, one of the various 
kinds of quartz-porphyry. Graduating toward and into obsidian 
through Pearlyte and Pitchstone. 

j. Pearlyte (Pearlstone, Lithoidal Rhyolyte) has a pearly lustre, 
often enamel-like; silica 70 to 80 p. c. G.=2°35-2°50; usually 
spherophyric, the spherulites consisting of orthoclase with quartz, 
silica constituting about 85 p. c. 

Rhyolyte is more common than trachyte, and occurs in the same and 
other regions. .Common in Hungary, the Siebengebirge; the southern ~ 
of the Lipari Islands; Iceland. Abundant in Nevada and the rest of 
the Great Basin between the Sierra Nevada and the Wasatch; the 
Yellowstone Park. (Hague and Iddings, Am, J. Sci., xxvii., 458, 1884.) 


16. Obsidian. ( Volcanic Glass.)—True glass, but more or © 
less microlitic. Colors gray, dull greenish, purplish to red, 
brown, and black. By increase of microlites becomes Pitch- 
stone (2etinile). Sometimes orthophyric, chrysolitic, often 
spherophyric. G. = 2°3-2°5. Contains 70 to 75 p. c. of 
silica, and has essentially the constitution of rhyolyte. 
Pumice is a finely scoriaceous variety with linear cells, con- 
taining 70 to 78 p. c. of silica. 

VARIETIES.—a. Glass-like in aspect, and splinters transparent. b. 
Semi-lithoidal, pitch-like in lustre (Pitchstone). ¢. Spherophyrie. 
d. Porphyritie (Vitrophyre). ec. Chrysophyric. f. Pumiceous (Pumice). 

Obsidian occurs with rhyolyte, in Hungary, the Lipari Islands, in 
Mexico, ete. Inthe N. W. part of the Yellowstone Park, N. of Beaver 
Lake, there is a high bluff of it capped by pumice; also a large area 
50 miles east of the bluff; the glass contains large spherulites, and 
also concentric concretions with irregular cavities between the lamine, 


DESCRIPTIONS OF ROCKS. AQT 


whose sides are often lined with small crystals of sanidin, tridymite, 
quartz, and occasionally fayalite (an iron chrysolite); some portions 
are porphyritic. (Iddings.) 


II. POTASH-FELDSPAR AND HORNBLENDE OR 
PYROXENE SERIES. 


1. Syenyte. (Syenite of Werner.)—Coarse granitoid to 
microgranitic; sometimes porphyritic. Consists of ortho- 
clase (often with microcline) and hornbiende, with no quartz 
or but little; also often contains biotite and some oligoclase. 
Silica 58 to 63 p.c. G. =2-7-2°9. Colors gray to flesh- 
red and dark gray. Hruptive; also metamorphic? 


VARIETIES.—a. Ordinary. b. Orthophyric. c. Containing oligoclase. 
d. Biotitic. e. Garnetiferous. f. Hpidotic. g. Pyroxenic. h. Zirconif- 
erous. For zircon-syenite, a kind containing elseolite, see p. 478. 

From Plauerschen Grunde, Saxony; the Hartz; Norway. A 
Norwegian afforded Kjerulf Silica 59°93, alumina 16:07, FeO 8°76, 
lime 4°56, magnesia 2°08, potash 2°82, soda 2°98, water 0°63 -= 97°82. 
Nearly all American syenite is of the quartz-bearing kind, Werner’s 
syenyte being (as says Zirkel for western America) ‘‘ extremely rare.”’ 


2. Quartz-Syenyte. (Syenyte of most early geologists. 
Hornblende-granite, Syenite-granite.)—Granitoid to micro- 
granitic; contains quartz, with the ingredients of the 
above-described syenyte. Silica 70 to 80 p.c. G. = 2°7- 
2°85. Metamorphic and eruptive. 


VARIETIES. Same asabove. Rather common in Archean regions 
in America, more so than in those of later age. Occurs at Quincy, 
Mass. (S. of Boston); red and gray, on the coast from Salem, Mass., to 
beyond Manchester; red at Grenville, Canada, containing little quartz; 
Barrow I., St. Lawrence; Frankenstein Cliff, White Mts, N. H., ete. 

The name Syenite is from the Egyptian Syene (modern Assouan), 
the place of the great quarries that afforded the red -granite-like rock 
for obelisks, the lining of pyramids, the columns of temples, sarcophagi, 
etc., and where there is an unfinished obelisk in its original position. 
The rock is mostly a red granite, consisting of red feldspar (orthoclase 
with some oligoclase), quartz, and mica, but having also some horn- 
blende in portions of it. Werner included under the term a horn- 
blende and orthoclase rock free of quartz (that of the Plauerschen 
Grunde), a kind not occurring in the region of Syene—and this is its 
restricted use nowin Germany. Brongniart and cthers defined it from 
the hornblendic variety in Egypt as consisting of feldspar, quartz, and 
hornblende, making the mica unessential; and this use of the term 
has been common out of Germany. 


&. Syenyte-gneiss.—Like gneiss in schistose structure 
and in mineral constitution, except that hornblende takes 


478 DESCRIPTIONS OF ROCKS. 


the place of mica. Some biotite often present. Graduates 
into amphibolyte. 


Common in the Archean regions of the Adirondacks; Canada; the 
Highlands of New Jersey and their extension southward and north- . 
ward, and also in other Archean regions. It is properly a schistose 
variety of quartz-syenyte, since structure is not a character of chief 
importance. 


4, Augite-syenyte.—Like syenyte, but containing, with 
the orthoclase, pyroxene in place of hornblende. Part of 
the pyroxene often changed to hornblende. 


Augite syenyte free from quartz occurs at Jackson, N. H. (Hawes), 
as an eruptive rock, the augite more or less altered to hornolende, and 
containing also biotite, titanic iron, apatite; at Mountain Pond, in 
Jackson, N. H.; Little Ascutney Mtn.; in southern Norway, with 
zircon-syenyte and graduating into it. 

Monzonyte, from Monzoni, is mentioned as a variety of augite- 
syenyte, in which the augite is partly uralitic, and there is much 
plagioclase (oligoclase to anorthite), with SiO, 48 to 59 p. cent.; it may 
be an orthoclase-bearing diabase. Glass in the base. Eruptive. 


5. Augite quartz-syenyte. (‘‘ Augite-granite.”)—Similar 
to the above, except in the presence of quartz. 


Occurs in the Archean region of Wisconsin (Irving, Van Hise), in 
all stages of gradation from the true augitic rock to a hornblendic, 
the latter a result of the alteration of the pyroxene to hornblende ; also 
in the Vosges, but containing more plagioclase than orthoclase. 

The gneissic form of this rock is far more common in Wisconsin 
than the granitoid ; and it occurs also in the Vosges. 

6. Unakyte.—Consists of reddish orthoclase and quartz, 
with yellow-green epidote in place of hornblende. Coarsely 
crystalline to fine in texture. In Cocke Co., Tenn., on the 
peaks ‘The Bluff,” <‘Walnut Mtn.,” and ‘‘ Max’s Patch,” 
and also in Madison Oo., N. C. (Ff. H. Bradley, Am. J. 
Sci., III., vii., 519, 1884). 


III. POTASH-FELDSPAR AND NEPHELITE ROCKS, 
HORNBLENDIC OR NOT. 


1. Zircon-syenyte.—Like syenyte, but contains also eleo- 
lite, with disseminated zircons; often also egirine, arfved- 
sonite, sodalite, eudialyte, eukolite, titanite, lencophane, 
etc. 


From Laurvig, Brevig, Fredericksviirn, etc., Norway; Marblehead 
peninsula, containing sodalite. tt 


DESCRIPTIONS OF ROCKS. 479 


2. Foyayte.—Coarse crystalline-granular ; also porphy- 
ritic; alsoaphanitic. Consists of orthoclase, reddish brown 
nephelite (elzolite) in 6-sided prisms and hornblende or 
egyrite, but no zircons; the porphyritic is orthophyric, and 
has a fine-grained base. 

From Mt. Foya and Picota in the Province Algarve, in Portugal; 
also on the east slope of Blue Mtn., N. J., between Beemersville and 
Libertyville, where it occupies adike + m. wide (B. K. Emerson, 1882). 
Contains egirite, titanite, sodalite. 

3. Miascyte.—Granitoid to schistose. Consists of micro- 
cline, eleeolite, biotite, with some quartz; often also zircon, 
pyrochlore, monazite, sodalite, cancrinite, etc. Meta- 
morphic? 

Named, by G. Rose, from Miask, men Mts., where it has a wide 
distribution. Occurs also on Pic Island, L. Superior; Litchfield, 
Me., containing cancrinite and sodalite, and lepidomelane in place or 
biotite. 

4, Ditroyte.—A coarse to fine-grained rock, consisting 
of microcline, nephelite (elxolite), and sodalite. 


From Ditro in Eastern Transylvania, where it is associated with 
syenyte and mica schist, and lies between these two rocks. 


5. Phonolyte. (Clinkstone.)\—Compact; gray, grayish 
blue, brownish gray; more or less schistose or slaty in 
structure; tough, and usually clinking under the hammer, 
like metal, when struck, whence the name. G.= 2°4-2°%. 
Consists of glassy orthoclase, with nephelite and some horn- 
blende. Sometimes porphyritic. Composition of the Bo- 
hemian phonolyte (G. Jenzsch): Sanidin (glassy orthoclase) 
53°55, nephelite 31°76, hornblende 9°34, titanite 3°67, 
pyrite 0:04 = 98°36. Rarely amygdaloidal. Accessory min- 
erals, oligoclase, pyroxene, nosite, hatiynite, leucite. Erup- 
tive only. 


Occurs in Auvergne; Brisgau; Bohemia. Not reported from N. 
America. 


IV. LEUCITE ROCKS, WITH OR WITHOUT AUGITE, 


Usually some sanidin (orthoclase) is present, and often 
also some nephelite and labradorite. 

1. Amphigenyte. (Leucitophyre.)—Consists of leucite 
(amphigene), augite, more or less glass, with often some 
ehrysolite, nephelite, sanidin, labradorite, brown mica 


480 DESCRIPTIONS OF ROCKS. 


(meroxene); accessory minerals, sodalite, haiiynite, nosite, 
melanite, magnetite. Dark gray to grayish black; fine- 
grained to scoriaceous and pumiceous; often leucitophyric. 
G. = 2:5-2°9. Silica 47-50 p. c.; but 50 to 58°5 with 
much feldspar. 

Varieties. —a. Fine-grained, with the leucite in grains. b. Leuei- 
tophyric. c. Sanidophyric. d. Nephelophyric. e. Hatiynophyrie 
(Haitynophyre). £. Chrysolitic (Leucite-basalt). g. Scoriaceous. 'The 
name amphigenyte was given 50 years since to the leucite-rock of the 
Vesuvian region by Cordier, and is as good as any of later origin. 
Constitutes for the most part the lavas of Somma and Vesuvius; also 
at Capo di Bove; the Eifel; the Albanian Mts.; the Erzgebirge at 
Bohmish-Wiesenthal, and elsewhere. Not yet found in America. 

2. Leucotephrite.—Like the above and occurring in the 
same regions, but containing much labradorite. 


3. Leucityte.—A grayish to greenish gray rock consist- 
ing of leucite crystals, and having a porous 

2331 leucitic ground-mass, with very little 

fy augite and some biotite (the large crys- 
we j tals in the figure annexed); also traces of 
AMigeweee] magnetite and biotite. Silica 54°42 p. ¢. 
ce “44 From Point of Rocks, Wyoming. An asso- 


SSS] ciated porous rock passes into a micaceou 
pumice. (Figure from Zirkel.) ; 





V. SODA-LIME-FELDSPAR AND MICA ROCKS. 


Kersantyte. (Mica-dioryte, Mica-porphyrite,  Soda- 
granite, Hemidioryte.)—Granitoid to fine-grained ; gray- | 
ish to brown and grayish black. Chiefly oligoclase and 
biotite, usually some quartz, hornblende, orthoclase, mag- 
netite, apatite; sometimes oligophyric. Silica 53 to 67 
p. c. Graduates, through the increase of hornblende and 
loss of biotite, into dioryte. 

From the Vosges, at Visembach and St. Marie ; porphyritic varie- 


ties (Mica-porphyrite) in Auvergne; Schwarzwald, ete. Granitoid, at 
Stony Point, on the Hudson, and near Cruger’s, in Cortlandt, N. Y. 


VI. SODA-LIME FELDSPAR AND HORNBLENDE OR 
PYROXENE ROCKS. 


The kinds of rocks here included differ chiefly in the 
kind of triclinic feldspar present—the minerals horn- 


DESCRIPTIONS OF ROCKS. 481 


blende and pyroxene (diallagic or not) having essentially 
the same composition. One series has oligoclase as the 
predominant feldspar, and another the more basic feld- 
spars, labradorite, anorthite. Under each there is great 
diversity in the kinds of rocks as to texture, for coarse- 
grained or granitoid, fine-grained, aphanitic, and glass- 
bearing varieties occur in each series, and sometimes (as 
shown by Hague and Iddings from Nevada investigations, 
and by Judd and Lotti) in the same eruptive mass. The 
oligoclase kinds often graduate into labradorite, obscuring 
distinctions, and sometimes also into orthoclase rocks, as in 
Wisconsin (Irving). The hornblendic kinds have in many 
cases resulted from the alteration of the pyroxenic (p. 451). 
The name ¢rap is a common and convenient designation 
of the dark-colored fine-grained pyroxene kinds, 

1. Dioryte. Quartz-Dioryte. (Greenstone in part.)— 
Typical dioryte: chiefly oligoclase and hornblende, with 
often some orthoclase and biotite; chlorite usually present 
in dark green varieties, and sometimes epidote. No glass 
present. Texture granitoid to aphanitic; often porphy- 
ritic ; sometimes spherophyric. Color often grayish white 
to greenish white for the coarser kinds; olive-green to 
blackish green and red for the finer. Very tough. Silica 
50-64 p. c., when free from quartz. G.= 2°66-3:0. 

The quartz-bearing and quartz-less kinds constitute two 
sections having similar varieties. Dark red, brownish red, 
and dark green porphyritic kinds, compact in base, have 
been called Porphyryte. Metamorphic and eruptive. 


VARIETIES.—a. Granitoid; granitelike in texture. b. Fine- 
grained. c. Aphanitic. d. Oligophyric (Porphyrite, Hornblende-por- 
phyrite), the base usually fine-grained to aphanitic, a red kind, the 
antique red porphyry, or ‘‘ Rosso antico” (Fig. 1, page 440). e. Schis- 
tose (Dioryte schist), usually chloritic. f. Micaceous, containing much 
biotite. 

Occurs in Saxony, Thuringia, Bohemia, the Vosges, and other 
parts of Europe, and often porphyritic; also in Scotland and Ireland; 
Mt. Dokhan, Egypt (the ‘‘ rosso-antico); in New York, on the Hud- 
son, north of Cruger’s, a granitoid kind having the hornblende prisms 
in some places 1-4 in. long, and graduating into a granitoid kersantyte; 
also at Littleton, Lancaster, and Lisbon, N. H.; W. and N. W. of 
Baltimore, where it has been derived from the alteration of ‘‘ gabbro” 
(G. H. Williams). A dioryte from the Hartz afforded Silica 54°65, 
alumina 15°72, Fe.O; 2°00, FeO 6°26, MnO trace, magnesia 5°91, 
lime 7°83, potash 3°79, soda 2°90, water 1°90 = 100°96. . 

Banatite and Tonalite are like quartz-dioryte in most characters. 


81 z 


482 DESCRIPTIONS OF ROCKS. 


Each contains some biotite, the latter much of it. Banatite is from 
the Ganat, and Tonalite from near Tonale, in the Southern Alps. 
Hemithrene is a dioryie containing calcite (and effervescing with 
acids); probably an altered dioryte. 

Mica-dioryte.—Dioryte often passes by a gradual disappearance of 
the hornblende, and the appearance of scales of black mica (biotite), 
into the non-hornblendic rock kersantite, called also mica-dioryte. 
See p. 480. 


2. Augite-Dioryte.—Containing augite with the oligoclase, 
and but little hornblende; the augite often more or less 
altered to hornblende. Colors dark gray to greenish black 
and black, without any glass. Hornblende-dioryte has 
often resulted from the alteration of augite-dioryte. 


Observed under partially altered form by Wichmann, Wadsworth, 
and Irving in northern Michigan and Wisconsin; occurs also in Cort- 
landt, N. Y., and on Stony Point, where it is partly altered to horn- 
klende-dioryte (G. H. Williams). 

Hypersthene-dioryte, a rather fine-grained rock containing hyper- 
sthene in place of augitce, but partly altered to hornblende, occurs also 
at Stony Point and in Cortlandt. Its mineral constitution is that of 
noryte. 

Ronin an greenish black fine-grained to aphanitic rock, often 
schistose, containing pyroxene in the form of diallage, with horn- 
blende and small crystals of oligoclase, some biotite, chlorite, epi- 
dote , sometimes spherophyric. Common at Biarritz and elsewhere 
in the Pyrenees. 


3. Labradioryte. (Labradorite-dioryte, Greenstone in 
part.)—Labradorite or anorthite with hornblende. Tex- 
ture usually fine-grained, crypto-crystalline to aphanitic, 
without glass. Color light grayish green to dark olive- 
green, blackish green or gray, and sometimes black. Very 
tough. G. = 2°8-3:1. Often contains chlorite and mag- 
netite. Metamorphic and eruptive. 


VARIETIES.—a. Granular crystalline. b. Compact, or fine-grained. 
c. Porphyritic; the feldspar in whitish or greenish white crystals dis- 
seminated through a fine-grained base, making a greenish ‘‘ porphyry.” 
d. Pyroxenic; containing some disseminated pyroxene. e. Magnetitic; 
containing magnetite or titanic iron. Occurs in the Urals; in Orange, 
west of New Haven, Conn., both massive and porphyritic; of black 
color in dikes at Compton Falls, N. H. (Hawes). The porphyritic 
variety—a metamorphic rock—afforded Hawes, Silica 48°61, alumina 
17°81, iron sesquioxide 0°25, iron protoxide 8°46, manganese protoxide 
0°20, lime 11°16, magnesia 7°76, soda 2°77, potash 0°47, water 1°63, 
titanium dioxide 1°35 = 100°47; G. = 3°01; the crystals of the porphy- 
ritic variety, according to an incomplete analysis by E. 8. Dana, consist 
of anorthite; they are mostly altered, and probably in the state of 
saussurite. 

Epidioryte consists of plagioclase with hornblende, some quartz, a 


DESCRIPTIONS OF ROCKS. 483 


little orthoclase, and some pyroxene. Silica 56 p.c. Chlorophyre of 
Quenast, Belgium, is related. 

An augite-dworyte containing labradoritein place of oligoclase is iden- 
tical in mineral composition with gabbro and basalt. 


4, Andesyte. (Hornblende-andesyte.)—Consists of oligo- 
clase or andesite and hornblende, with often some orthoclase 
or sanidin, and biotite. Sometimes porphyritic. Color 
usually dark to light green, and gray, sometimes purplish; 
aspect more or less trachytic. Some glass in the base, as 
in lavas. Silica 59-63 p.c. G. = 2°6-2°7. Texture varies 
from coarsely crystalline to microcrystalline, trachytic, 
rhyolitic, glassy, scoriaceous, and at Washoe, Nevada, these 
wide extremes exist in the same eruptive mass, according 
to Hague and Iddings. 


5. Dacyte. (Quartz-andesyte.)—Like the above, but 
containing disseminated quartz grains, and sometimes 
quartzophyric. Silica 65 to 70 p.c. Often graduates into 
the orthoclase rock, rhyolyte. 


Varieties of Andesyte and Dacite.—a. Fine-grained. b. Porphy- 
ritic. ¢c. Micaceous (Hornblende mica-andesyte). d. Hypersthenic. e. 
Scoriaccous. f. For dacyte, guartzophyric. 


From the Andes in Cotopaxi, Chimborazo, etc. Common, espe- 
cially the dacyte, over the Great Basin, in Nevada and _ elsewhere, 
and in the voleanoes of the Pacific border. Propylyte, of Nevada, is 
altered andesyte, as first pointed out by Wadsworth. 

Timacyte is labradorite-andesyte, from Timokthale, Bulgaria. 


6. Augite-Andesyte.—Contains the same feldspars as an- 
desyte; but augite is present, and often hypersthene, in 
place of hornblende, but often is in part changed to horn- 
blende. Amount of silica 56 to 61 p.c., or 62 to 77 from 
the presence of quartz. More or less glass present. Tex- 
ture crystalline, granular to aphanitic and fluidal; also 
glassy, and resembling pearlyte and obsidian, and sphero- 
phyric. Hruptive. 


VARIETIES.—There are two series: A. Ordinary, that is, without 
chrysolite, or only in traces, B. Chrysolitic, chrysolite being in dis- 
seminated grains or crystals. Under each there are varieties. a. O7- 
dinary. b. Horntlendic (Hornblende-augite-andesyte). ¢. Chloritic, 
containing disseminated chlorite and feeble in lustre. d. Amygdaloidal 
(and chloritic). e. Porphyritic. The chrysolitic variety is one of the 
rocks that has been called Melaphyre. Reported from the Great Basin, 
but much of the rock there is hypersthenic, and belongs to the follow- 
ing. Trachy-doleryte is essentially augite-andesyte; a felsytic variety 
occurs among the English Cumberland lavas. 


484 DESCRIPTIONS OF ROCKS. 


7. Hypersthene-Andesyte.—Like augite-andesyte, and 
may be considered a variety containing hypersthene in 
place of most of the augite. Color gray, bluish gray, red- 
dish, black. G. = 2°6-2°7. Often porphyritic. Some- 
times chrysolitic. Passes into glassy and pumiceous varie- 
ties. 

Constitutes part of the rock of Buffalo Peaks, Colorado, and of an- 
desyte localities in the Great Basin; common rock at Mt. Rainier and 


Mt. Hood, Mt. Shasta, at Washoe, Nevada. When chrysolitic, near 
basalt in its characters. 


8. Hyperyte. (Hypersthene-gabbro. Noryte in part.)— 
Granitoid. Consisting chiefly of labradorite or anorthite, 
with hypersthene, usually some pyroxene; also biotite and 
magnetite; sometimes, chrysolitic. 


From the Hartz; Hitterot, Egcersund, Norway; St. Paul, coast of 
Labrador; West and N. West of Baltimore, Md. 


9. Gabbro. Granitoid; consisting chiefly of labradorite 
and pyroxene, often a diallagic variety ; often contains 
some hornblende; also magnetite or ilmenite; sometimes 
chrysolitic. No glass. Color dull flesh-red to brownish 
red and dark gray. G. = 2°7-3:1, varying with the pro- 
portion of pyroxene, which is sometimes small. ‘The 
chrysolite is often in part changed to serpentine. 

VARIETIES.—a. Granitoid. b. Feldspathic, the amount of pyrox- 
ene small. c. Chrysolitic (Olivine-gabbro), containing disseminated 
chrysolite, which is often more or less changed to serpentine. d. 
Microcrystalline, and thus graduating insensibly into doleryte or basalt. 
Common in the Adirondacks and the Archean of Canada; Waterville, 


N. H., where it is chrysolitic, and is associated with an altered variety 
containing serpentine’ also on Mt. Washington River. 


The name Gabbro is of Italian origin. It is now, and has long 
been, used in Italy for a green serpentine rock. Signor Lotti says 
(1885) that it is not possible there to adopt the perverted use of lithol- 
ogy. Gabdbro rosso in Italy is a reddish altered gabbro. The name 
Huphotide in Italy covers a labradorite rock like the above in mineral 
constitution, and also the same in which the labradorite is altered to 
saussurite, the former graduating into the latter. 


10. Doleryte-—Texture varying from a rather fine-grained 
granitoid to aphanitic; often granulitic through the interior 
of the eruptive mass, and aphanitic and glass-bearing along 
the walls where cooled rapidly; also rhyolitic, and scoria- 
ceous. Consists, like gabbro, of labradorite and pyroxene, 
with the pyroxene sometimes. diallagic; often porphyritic; 
often contains chrysolite (olivine); and magnetite or me- 


DESCRIPTIONS OF ROCKS, 485 


naccanite in minute grains. Color dark gray to grayish 
black, greenish black and brownish gray, black ; G. = 2°75- 
3°1. Includes the most of what is called trap. Chryso- 
litic kinds sometimes altered to impure serpentine. 


Vanrieties,—A. Diabase. Granitoid to fine-grained and aphanitic; 
the granitoid varicty essentially like gabbro. Free from glass. Often 
chrysolitic. Often chloritic and amygdalcidal (Spilyte). Often 
labradophyric, sometimes anorthophyric. Often augitophyric. Oc- 
casionally contains quartz. Graduaies impcrceptibly into the fol- 
lowing: 

B. Basalt. Granulitic to aphanitic (Anamesyte) and scoriaceous. 
Glass present. Otherwise as above. Lavas, stony and scoriaceous, 
here included. Quarizophyric, at Lassen’s Peak (Diller). 


Abundant in most regions of volcanic and other igneous rocks. Con- 
stitutes the trap ridges of the Connecticut Valley, Palisades on the Hud- 
son, and similar 1idges in Nova Scotia, Pennsylvania, Virginia and N. 
Carolina, where some are chloritic and amygdaloidal ; also covers 
large areas over the western slope of the Rocky Mountains. An anor- 
thophyric variety at East Hanover, N. H., has anorthite crystals 4+ to# 
in. broad, and same occurs also at Moose Mtn. and in Stark, N. H., and 
at Concord, Vt.; and with crystals 4 in. of anorthite, and distantly 
spaced, in the Buttress dike crossing West Rock, Woodbridge, and 
Orange, near New Haven, Ct. On the use of the term diabase see 
p. 445. Palatinite is related to the above. 

The ‘‘ antique grecn porphyry,” or Porfido verde antico, figured on 
page 440, in Fig. 2, is a porphyritic doleryte or diabasc, the feldspar 
being labradorite, and the other chief constituent, augite, with also 
some chlorite or viridite, which last is the source of the greenish 
color. Itis from the South Morea, between Lebetsova and Marathon- 
isi. Delesse obtained, from the compact base, Silica 53°55, alumina 
19°34, iron protoxide 7°35, manganese protoxide 0°85, lime 8°02, soda 
and potash 7°93, water 2°67. In view of its firmness, and its contrast 
in this respect with most chloritic doleryte, it may be queried whether 
the rock is not a metamorphic doleryte. It closely resembles the por- 
phyritic labradioryte from the vicinity of New Haven, Conn. (which 
is chloritic and metamorphic), though differing from it in, containing 
pyroxene instead of hornblende. A similar porphyry is reported from 
Elbingerode in the Hartz, Belfahy in the Vosges, and Barnetjern near 
Christiania in Norway. 

The name Melaphyre was first used for a black porphyry described 
as having feldspar crystals in a compact hornblendic base ; since, for 
dark augite-oligoclase rocks (dioryte or andesyte), porphyritic or not ; 
compact augite-labradorite rocks (diabase or doleryte), non-porphyrit- 
ic ; the same, chrysolitic, and amygdaloidal or not. Like anamesyte 
and spilyte, it is not needed in petrography. 

11, Tachylyte. (AHyalomelan.)—Blackish glass, or pitch- 
stone, connected with augitic igneous rocks or lavas; some- 
times porphyritic; often contains grains of augite or chrys- 
olite. The former affords on analysis 55 per cent. of 
silica, and the latter 50 to 55, 


486 DESCRIPTIONS OF ROCKS, 


Tachylyte is from Siisebiihl, Germany; north shore of L. Superior, 
etc.; Hyalomelan from a volcanic rock in the Vogelsgebirge. Sider- 
omelan is a tachylyte from Iceland. Limburgyte is an augitic glass. 

12. Eucryte.—A doleryte-like rock, consisting chiefly of 
anorthite and augite, with sometimes chrysolite. Occurs 
granitoid to fine-grained, and as a lava. 3 

From Elfdalen, Norway; Puy de Dome, France; Carlingford, Ire- 
land, etc. 

Troctolyte consists of anorthite and chrysolite, with some augite. 

13. Corsyte. (Ordicular Dioryte.)—Anorthite and horn- 
blende with some quartz and biotite. Spherophyric, and 
consisting chiefly of concretions of anorthite and hornblende 
with a little quartz. 


From Corsica; the Shetlands; Bohemia; Yamaska Mtn., Canada. 


14. Anorthityte.—Coarsely crystalline-granular. Consists 
largely of anorthite, or a feldspar near it in composition. 
Light gray to white or faintly greenish; an occasional trace 
of augite and chrysolite. An analysis of the “ anorthite” 
gave the oxygen ratio 1: 2°4:4:15, with about 47 p. c. of 
silica, showing divergence from anorthite (Irving). 

On the N. shore of L. Superior, between Split Rock River and the 


Great Palisades, and in Carlton’s Peak, near the mouth of Temperance 
R. Eruptive. (Anorthite-rock of Irving.) 


15. Nephelinyte. (Nepheline-doleryte, Tephryte.)—Ne- 
phelite with augite and some magnetite; with or without 
chrysolite; often nephelophyric. Ash-gray to dark gray. 
Frequent accessory minerals, leucite, hatitynite, sanidin, bio- 
tite, hornblende, etc. : 

VARIETIES.—a. Ordinary. b. Nephelophyric. c. Chrysolitic (Ne- 


pheline-basalt). d. Plagioclase-bearing (Nepheline-tephryte). e. Meli- 
litic (Melilite-basalt). f. Haiiynitic. g. Hornblendic (Buchonite). 


Occurs at Katzenbuckel, in the Oderwald, Eifel, Schwarzwald, 
etc. 

16. Teschenyte.—Felsytic in texture; dark bluish green. 
Consists chiefly of anorthite or labradorite, nephelite, horn- 
blende, and augite. The hornblende sometimes in large 
black prisms. Accessory minerals black mica, apatite. 


From Tetschen, Moravia. 


DESCRIPTIONS OF ROCKS. 487 


C. SAUSSURITE ROCKS. 


Euphotide. (Gaddro in part.) Grayish white to gray- 
ish green, and sometimes olive-green; very tough. G. = 
2°9-3°4. Consists of saussurite with diallage or smaragdite; 
the saussurite often accompanied by labradorite, or other 
triclinic feldspar; Silica 43 to 52 p. cent. The saussurite 
probably altered labradorite or other triclinic feldspar, and 
the smaragdite altered diallage. Graduates into gabbro, a 
related rock in which the labradorite is unaltered, and also 
into the finer grained labradorite-rocks of similar constitu- 
tion, diabase and basalt; in Italy both the euphotide and 
gabbro are called euphotide. Chrysolite is often present, 
as in gabbro, and also serpentine as a result of the altera- 
tion of chiefly the chrysolite. Altered eruptive (Lotti). 

VARIETIES.—a. Diéallagic; diallage the chief foliated mineral. 
b. Smaragdilic ; emerald-green smaragdite, the foliated mineral. 
ce. Micaceous; contains mica. d. Chrysolitic. e. Serpentinous. f. 
Garnet'ferous, g. Schistose ; especially when tale is present. h. 
Spherophyric ; contains aphanitic concretionary spheroids of the saus- 
surite mineral, as in the ‘‘ Variolite de la Durance,” and of Mt. 
Genévre, and associated with ordinary euphotide. The variety ob- 
tained at Orezza is the Verde di Corsica, of Cecorative art. - 

Occurs near Lake Geneva, in Savoy; at Mt. Gen¢vre in Dauphiny, 
near the boundary between France and Italy; at Allevard, in the 
northeastern part of Iscre; in the valley of the Saas, north of east of 
the Monte Rosa region ; in the Grisons ; near Leghorn and Bologna ; 
a eee at Mt. lmpruneta; Corsica, in the Orezza valley; Silesia; 

. of Unst. 


D. ROCKS WITHOUT FELDSPAR. 


1. GARNET, EPIDOTE, TOURMALINE ROCKS. 


1. Garnetyte. (Garnet Rock.) Massive fine-grained gar- 
net. Color yellowish or buff to greenish white. Tough. 
Gao atvoo 4. HH. = 7-0. 

From Vieil Salm, Belgium, a manganesian garnet (Renard), being 
the superior yellowish novaculite or razorstone, where it makes layers 
in a hydromica (scricite) schist; St. Frangois and Orford, Canada, an 
alumina-lime garnet (Hunt). 

2. Eclogyte. (Omphacite.)—Fine-grained granular rock, 
consisting of red garnet in a base of grass-green smaragdite, 
with occasionally zoisite, actinolite, and mica, Very tough. 


488 DESCRIPTIONS OF ROCKS. 


Also essentially the same rock, of dark color, consisting of 
reddish or brownish yellow garnet with black or greenish 
black hornblende and some magnetite. 

3. Epidosyte—Compact, pale green to pistachio-green. 
Very tough and hard. Consists of epidote and quartz. A 
variety from the Shickshock Mts., Gaspé, of a pale yellow- 
ish color, has H. = 7 and G. = 3°04-3°09 (Hunt). 

4, Tourmalyte. (Schorl Rock.)—Granular and compact 
schistose. Consists of tourmaline and quartz, with often 
chlorite, mica, and sometimes tin-ore. Occurs massive in 
Cornwall; schistose at Eibenstock, in Saxony; in Marble 
Mtn. and Ragged Ridge, Warren Co., N. J. (G. H. Cook). 


2. HORNBLENDE, PYROXENE, AND CHRYSOLITE ROCKS, 


In these rocks chrysolite when present is often changed 
to serpentine, and sometimes the pyroxene also. 

1. Pyroxenyte.—Consists of augite, coarse or fine crystal- 
line-granular. Sometimes chrysolitic. Cortlandt, N. Y., 
and Stony Point. | 

2. Picryte.—Blackish green, grayish to brownish red. 
Orystalline-granular. Consists of chrysolite, with augite 
or diallage or hypersthene; the augite sometimes in crystals; 
often partly altered to serpentine; also some magnetite. 
Graduates into chrysolitic basalt. Changes to hornblende- 
picryte, and into a serpentine rock. From the Fichtelge- 
birge. ulysyle contains also garnet; Sweden. 


Limburgyte has the same constituents, but is glassy. Silica 48 p. c. 
From Limburg in the Kaiserstuhl. 


3. Lherzolyte.—Greenish gray; crystalline-granular. 
Consists of chrysolite, enstatite, whitish pyroxene with 
chrome-spinel (picotite) and sometimes garnet. Partly 
altered serpentine. From Lake Lherz. 

4, Amphibolyte. Hornblendyte.—Coarse to fine crystal- 
line-granular. Hither massive or schistose. Some kinds 
chrysolitic. Occurs as a metamorphic rock as well as erup- 
tive. Sometimes derived from the alteration of an augitic 
rock. A paler green variety, consisting of actinolite, has 
been called actinolyte. 

VARIETIES.—a. Massive, coarse crystalline. b. Fine crystalline. 
c. Aphanitic. d. Chrysolitic. e. Actinolyte ; consisting of pale green 
hornblende. f. Schistose ; Hornblende schist. 


DESCRIPTIONS OF ROCKS, 489 


Common as a schist and massive rock in metamorphic regions. A 
coarsely crystalline, chrysolitic eruptive rock at Stony Point, on the 
Hudson River, and on the opposite side of the river in Cortlandt, N. Y. 

5. Hornblende-Picryte.— Dark greenish to greenish black 
and gray; coarse to fine grained. Consists of hornblende, 
chrysolite, and serpentine, with magnetite; the hornblende 
mostly or wholly altered augite and the serpentine altered 
chrysolite; usually more or less augite. From Anglesey 
and Carnarvonshire. . 


6. Dunyte. Peridotyte—Pale green, grayish green, 
granular; consisting almost wholly of chrysolite; often 
partly changed to serpentine. G.= 3-3:1. 

From Mt. Dan in New Zealand, where it is eruptive. Also from 


Macon Co., N. Carolina. A related rock is supposed to be the origin 
of the serpentine rocks of Baste in the Hartz, etc. 


7. Glaucophanyte.—Consists chiefly of the blue soda- 
bearing hornblende, glaucophane, with some black mica. 


From Saxony; Isle of Syra; New Caledonia; Coast region, Cali- 
fornia (Becker). An epidotic variety is reported from the Alps. 


E. HYDROUS MAGNESIAN AND ALUMINOUS ROCKS. 


1, Chlorite Schist—Schistose; color dark green to grayish 
green and greenish black; but little, if any, greasy to the 
touch. Consists of chlorite, with usually some quartz and 
feldspar intimately blended, and often contains crystals 
(usually octahedrons) of magnetite, and sometimes chlorite 
in distinct scales or concretions. Metamorphic. 

VaRtieties.—a. Ordinary. b. Hornblendic; the hornblende in 
grains or needles. c. Magnetitic. d. Tourmalinic. e. Garnetiferous. 
f. Pyrorenic. g. Staurolitic. h. Hpidotic. Graduates into argillyte. 

2. Chlorite-Argillyte-—An argillyte or phyllyte consisting 
largely of chlorite. Metamorphic. 

3. Talcose Schist—A slate or schist consisting chiefly of 
tale. Not common, except in local beds, most of the so- 
called “‘ talcose slate” being hydromica schist. Listwianyle 
is a variety, from the Urals, consisting of tale and granular 
quartz. 

4. Steatyte, Soapstone (p. 326).—Consists of tale. Mas- 
sive, more or less schistose; granular to aphanitic. Color, 
gray to grayish green and white. Feels very soapy. Lasily 
cut with a knife. Metamorphic. 


490 DESCRIPTIONS OF ROCKS. 


’ VARIETIES.—a. Coarse-granular, and massive or somewhat schis- 
tose. b. bine-granular, ‘‘ French chalk.” c. Aphanitic, or Rens- 
selaerite ; of grayish-white, greenish, brownish to black colors, from 
St. Lawrence Co ounty, N. ven and Grenville, Canada. 


5. Serpentine—Aphanitic or hardly granular. Lasily 
scratched with a knife. Dark green to greenish black in 
color, and often a little greasy to the feel on a smooth sur- 
face, but sometimes white, pale grayish, yellowish green, 
and mottled. Metamorphic. 


Vanieties.—a. Noble; oil-green and translucent. b, Common ; 
opaque, and of various colors. c. Schistose. d. Diallagie ; contains 
green or metalloidal diallage. e. Chromiferous ; contains chromite, 
a chromium ore belonging to serpentine regions. f. Bastitie ; contains 
basiite or enstatite. g. Garnetiferous ; contains garnet, as at Zoblitz. 
h. Chrysolitic ; contains chrysolite. i. Brecciated ; consists of united 
fragments. (See also page 330.) Serpentine often has a crystalline- 
granular texture, and sometimes a foliated, which it owes to the 
mineral from which it was made, as chlorite, enstatite hypersthene, 
pyroxene, hornblende ; which minerals often occur in if in a’ half- 
altered state. 


6. Ophiolyte. (Verd-Antique Marble, Ophicatce.)—A 
mixture of serpentine with limestone, dolomite, or magnes- 
ite, having a mottled green color. Often contains dissemin- 
ated magnetite or chromite. Metamorphic. 


VARIETIES.—a. Calcareous ; the associated carbonate being calcite. 
b. Dolomitic ; the associated carbonate, dolomite. c. Magnesitic ; the 
associated carbonate, magnesite. Either of these kinds may contain 
chromite or magnetite. Handsome verd-antique marble has been ob- 
tained near New Haven and Milford, Conn. A beautiful variety, hay- 
jng pure serpentine disseminated in grains or spots through a whitish - 
calcite, occurs at Port Henry, Essex County, N. Y., and is worked. 


7. Pyrophyllyte and Pyrophyllite Slate.—Like the pre- 
ceding in appearance and soapy feel, but having the com- 
position of pyrophyllite (p. 328). The color is white and 
gray or greenish white. Occurs in North Carolina. One 
of the varieties from the Deep River region is used for slate- 
pencils. Metamorphic. 


The iron ores, hematite, magnetite, limonite, siderite, have rightly 
a place among rocks, as they constitute beds in the earth’s strata. But 
they have already becn sufficiently described. 


DURABILITY OF ROCKS. 491 


VI. DURABILITY OF ROCKS. 


1. Sources of Weakness. —The durability of arock depends 
mainly on (1) its degree of porosity or soundness; and (2) 
the presence or absence of a mineral of easy destruction or 
easy removal. 

The porosity may be general in the rocks, or differ along 
different planes or lamin, or be connected in part with the 
presence of a fissile mineral like mica, or be increased by 
rifts or cracks. As far within the rock as water and air can 
et access together, disintegration or decomposition will 

€ going on, whatever the rock. Water by itself protects 
rocks—as is often seen on rocky seashores where the rock 
below half-tide may be unchanged, and that above deeply 
decayed. 

The weak mineral of a rock may be— 

A. One that is soluble, and hence removable, by waters 
containing either carbonic acid, which is present in all 
waters, or organic acids, which are always present in waters 
filtermg through soils. Calcite is one such mineral. 

B. One that contains a removable constituent, such as an 
alkali or lime, e.g., orthoclase, which loses its potash through 
infiltrating acid (carbonic or organic) waters, and thence’ 
changes to clay or kaolin. 

C. One that contains iron in the protoxide state, such 
iron tending to oxidize further and pass to the sesquioxide 
state, producing limonite of iron-rust color, or (less fre- 
quently) hematite of a red color; e.g., black mica, pyroxene, 
hornblende. 

D. One that contains iron combined with sulphur, which 
iron tends to pass to the sesquioxide state, as under C; but 
as the sulphur also oxidizes into sulphuric acid, iron sulphate 
may result; e.g., pyrite, pyrrhotite, marcasite. 

Porosity and the presence of rifts or cracks give an op- 
portunity for these methods of destruction by solution and 
oxidation to act. In an exposed ledge, the depth to which 
oxidation, or loss of firmness, extends is an indication of 
the depth of porosity. In some granites the depth (or the 
thickness of the sap, as the quarryman sometimes calls it) 
is a yard or more; in the best, a line or less. 


492 DURABILITY OF ROCKS, 


The methods of decay are then as follows: 

a. By method A: as when a crystalline limestone, if it is — 
a dolomite containing some calcite-{p. 460), loses its calcite 
through infiltrating waters and crumbles to sand—a common 
fact in Westchester Co., N. Y., Berkshire Co., Mass., and 
many other regions. | 

6. By method B: as when a granite has its feldspar weak- 
ened or turned to kaolin, and becomes weak or crumbling. 

c. By method C: as when granite has its black mica 
rusted and destroyed, causing the rock to become a granite 
sand consisting of feldspar and quartz—a common occur- 
rence; or when trap, a rock consisting of a feldspar (labra- 
dorite) and pyroxene, becomes changed more or less deeply 
to rusty rock or rusty earth; the depth hardly a line in the 
most anhydrous and durable, but many yards in the poorer 
hydrous kinds. 

d. By method D: as when any rock, of the legion con- 
taining pyrite, has the pyrite rusted (oxidized) and changed 
to limonite or hematite, or to sulphate, to the discoloration 
and decay of the rock—a very common evil in carelessly se- 
lected building-stones. 

Besides these there are also several mechanical sources of 
destruction attending methods B, C, D, owing their effi- 
ciency to the fact that the introduction of material among 
grains or into rifts, by chemical change or otherwise, is an 

“introducing of wedges, pushing the grains apart, and open- 
ing and extending rifts. 

These are the following: 

e. In method B, the feldspar loses silica as well as al- 
kali,—at least one third of its 66 p. c.,—and this may de- 
posit about the grains, or in the rifts of the rock deepening 
and multiplying them, and be so infinitesimal in amount 
that it is only with difficulty detected. 

f. In method C, oxygen is introduced, and the resulting 
oxide with the rest of the mineral takes more space than 
the unaltered mineral; and here again there is a wedging or 
divellent action. 

g. In method D, besides the same action as under f, the 
sulphuric acid formed may combine with alkalies, lime, iron, 
alumina, present in the rock, and make other wedges, be- 
sides adding directly in a chemical way to the destructive 
action. 

In addition, there are other mechanical methods of de- 


DURABILITY OF ROCKS, 493 


cay which work either molecularly or in the large way. 
These are: 

h. Alternate heating and cooling, from changes in tem- 
perature between exposures to sunshine and shadow, day and 
night, warm seasons and cold, sun’s heat on rocks during 
the day and the cold waters of the returning tide, and so 
on, causing expansion and contraction, and thence superfi- 
cial disintegration of granule after oranule; or the separa- 
tion of scales or plates parallel to the surface; or producing 
a laminated or jointed structure on a large scale, as in some 
granitoid rocks (e.g., the concentric structure of the Yose- 
mite granite peaks). The unequal expansion caused by a 
given amount of heat in the different minerals of a granite 
is supposed to enhance the disintegrating effect. 

7. The freezing of water; expansion taking place on 
freezing (p. 251), exerting a tearing action, both among 
surface grains and in rifts or fissures, and covering tho 
slopes beneath rocky blufis in cold climates with débris. 

j. The growth of microscopic life (as microbes and mi- 
nute alge or fungi) in rifts and pores introduces growing 
wedges, having a tearing action, extending rifts, etc. 

The erowth of roots and stems of larger plants wedges 
open rifts and joints on a large scale, sometimes moving 
blocks weighing hundreds of tons. 

k. Further, organic material, living and dead, is the oc- 
casion of destruction by chemical means. The living may 
give out oxygen and carbonic acid; and the dead may pro- 
duce by their decay organic acids, “carbonic oxide, and car- 
bonic acid. Moreover, the living microbes may, according 
to their kinds, promote oxidation and deoxidation, nitrifica- 
tion and denitrification, and so be the initiator of change and. 
destruction, as they are of fermentation and decay, and a 
medium of right functional action in the processes of life. 

Rocks have often retained the glacier markings upon 
them perfectly fresh until now, when they have had a cov- 
ering of two or three feet of earth; and they have lost such 

mar kings after a few years of exposure. This happens often 
without true decomposition or oxidation. The preservation 
of the scratches may be due partly to the water of the soil, 
but also in part, and perhaps most largely, to freedom from 
the expansion and contraction which is caused by changing 
temperature. 

In granite and sandstone, the less mica the more durable 


494 DURABILITY OF ROCKS. 


the rock, because mica tends to increase porosity. In all 
firm rocks, closeness of texture or fineness of grain is fa- 
vorable to durability. There is no more durable rock than 
a good roofing slate. Good granites, when well polished, 
will usually resist all weathering agencies; because the pol- 
ished surface has no depressions to catch and hold water, 
but dries almost immediately after wetting. 

To ascertain the durability of a rock, the first step is to 
examine the rock in its native ledges; if durable there, 
it will be durable in man’s structures, and not otherwise. 
The practice of testing the durability of a stone for archi- 
tectural purposes by putting it into water, and then weigh- 
ing it, after some days of exposure, to see whether it has 
gained in weight, is a good one. Durability depends much 
on the climate. In Peru even sunburnt bricks will last 
for centuries. 

2. Lesistance to Crushing.—The resistance to crushing 
in rocks is ascertained by subjecting cubes of a given size 
to pressure; for the best results the pressure should be very 
slowly applied. In recent experiments by P. Michelot,* 
Minister of Public Works in France (whose trials num- 
bered over 10,000), the most compact limestones, weighing 
2700 kilograms per cubic metre, were crushed by a weight 
of 900 kilograms per square centimetre. Compact odlitic 
limestone of Bourgogne and some other French localities, 
weighing 2600 to 2700 kilograms, bore 700 to 900 kilograms 
before crushing. Statuary and decorative marbles bore 500 
to 700 kilograms. 

Of granitic rocks from Brittany, the Cotentin, the Vosges, 
and the Central Plateau of France, weighing 2600 to 2800 
kilograms, the hest, which admitted of polishing, bore 1000 
to 1500 kilograms; while the coarser granites of Brest and 
Cherbourg and the syenyte of the Vosges bore 700 to 1000 
kilograms; and other coarse granites, in which the large 
crystals of feldspar were in part decomposed, bore only 400 
to 600 kilograms. The green porphyry of Ternuay (Haute 
Sadne), bore 1360 kilograms; the basalt of Estelle (Puy de 
Dome), 1880 kilograms. 

In trials by Gen. Gilmore, trap of New Jersey required 
to crush it 20,750 to 24,040 pounds a square inch; granite 


* Exposition Universelle de 1873 & Vienne, pp. 401-432; and Annales des Ponts 
et Chaussées, 1863, 1868, 1870. 


DURABILITY OF ROCKS. «° 495 


of Westerly, R. I., 17,750; id. of Richmond, Va., 21,250; 
syenyte of Quincy, 17,750; marble of Tuckahoe, N. Y., 
12,950; id. of Dorset, Vt., 7612; limestone of Joliet, IIl., 
11,250; sandstone of Belleville, N. J., 10,250; id. of Port- 
land, Ct., 6950; id. of Berea, O., 8800; id. of Amherst, O., 
6650; id. of Medina, N. Y., 17,250; id. of Dorchester, N. B., 
$150. | 

Trials of Archean granites in Minnesota, by Mr. J. Co- 
Crvit gave 26,200 pounds per square inch for the mean of 
20 samples, and 23,318 pounds when crushed between 
wooden cushions. 

When absorbent rocks are thoroughly wet the weight re- 
quired to crush them is greatly reduced. Crushing of wet 
chalk, according to trials by Delesse, required only one 
third what the stove-dried required; and for the limestone, 
_‘‘calcaire grossier,” of Vitry and other : localities, mostly 
one third to one half. 'Tournaire and Michelot found, for 
the chalk of the Paris basin, the pressure required when wet 
two ninths of that required when the rock had been dried 
at a temperature considerably above 212° I. 


ACADEMY MINERAL COLLECTION. 


For the convenience of instructors in Academies or 
High. Schools, a catalogue is here inserted of the more 
desirable species. The collection, made up according to 
it, would include 125 specimens. ‘The cost will depend on 
the size and quality of the specimens: with specimens aver- 
aging in size 2 X 24 inches, it need not exceed twenty dol- 
lars; andif made forty dollars, it should obtain an excellent 
collection, the specimens averaging 3 x 3 inches, and many 
of them crystallized. The number following the name of 
each mineral is that of the page where described. 


1. Sulphur, 106; > © -. «+ 5,12. Malachite, 154. 

2. Stibnite, 112. 13. Galenite, 160. 

3. Graphite, 119. 14. Pyromorphite, 167. 
4. Gold in quartz, 122. 15. Cerussite, 168. 

5. Silver, 129. 16-18. Sphalerite: black, yellow, 
6. An ore of Silver. etc., 170. 

7. Cinnabar, 143. 19. Zincite, 171. 

8. Copper, 145. 20. Willemite, 173. 

9. Chalcopyrite, 147. 21. Calamine, 174. 

10. Tetrahedrite, 150, 22. Cassiterite, 176. 
11. Cuprite, 151. 23. Rutile, 179. 


496 


24, Garnierite, 185. 
25-27. ap yw crystals, massive, 
9 


28. Pyrrhotite, 192. 

29. Arsenopyrite, 192. 

30-382. Hematite: crystallized, 
massive, red ochre, 198. 

33. Magnetite: crystals, massive, 


34. Franklinite, 197. 

85. Chromite, 197. 

36-38. Limonite: 
botryoidal, 
bog ore, 198. 

. Columbite, 201. 

. Siderite, 203. 

; Pyrolusite, or other Man- 

ganese oxide, 206, 207. 

. Corundum, 211. 

. Spinel, 213. 

. Cryolite, 216. 

. An Alum, 217. 

é Magnesite, 226. 

. Fluorite, 227, 

48-50. Gypsum: crystal, selenite, 
massive, 229. 

51. Anhydrite, 230. 

54. Apatite, 2382. 

55-60. Calcite: cryst., cleavage, 
rhombohedron, staiagmite, 
marble, common limestone, 
chalk, 235. 

61. Aragonite, 237. 

62, 68. Dolomite: 
Marble, 2388. 

64, Barite, 240. 

65. Celestite, 242. 

66. Halite, 248. 

67-74. Quartz: cryst., milky, 
smoky, chalcedony, agate, 
hornstonce (or flint or chert), 
jasper, 2538. 

75, 76. Opal: common, tripolite, 

a) e 


stalactitic. or 
yellow ochre, 


Pearl Spar, 


ACADEMY MINERAL COLLECTION. 


77, 78. Pyroxene: cryst., massive 
cleavable, 265. 

79. Rhodonite, 268. 

80. Spodumene, 269. 

81-84. Hornblende: black, green 
(actinolite), white (tremo- 
lite), asbestus, 270. 

85. Beryl, 274. 

86. Chrysolite, 277. 

87-89. Garnet: crystals, crystals 
in the rock, 278. 

90. Zircon, 281. 

91. Vesuvianite, 282. 

92. Epidote, 288. 

93. Zoisite, 285. 

94, 95. Muscovite, 288.. 

96. Biotite, 291. 

97. Scapolite, 292. 

98. Albite, 299. 

99, 100. Orthoclase: cryst., cleav- 
able piece, 300. 

101, 102. Tourmaline, 804, 

108. Andalusite, 806. — 

104, Cyanitc, 308, 

105. Topaz, 309. 

106. Sphene, 312. 

107, 108. Staurolite: cryst., one 
cruciform, 313. 

109. Apopbyllite, 316, 

110. Prehnite, 317. ; 

111. Natrolite, 321. 

112. Chabazite, 322. 

118. Stilbite, 824. 

114-116. Talc: foliated, massive 
(soapstone), French chalk, 
or rensselacrite, 826. 

117. Glauconite, 329. 

118,119. Serpentine, 829. 

120. Kaolinite, 382. 

121. Chlorite, 339 or 840. 

122, Asphaltum, 349. 

123. Anthracite, 350, 

124. Bituminous Coal, 351. 

125. Cannel Coal, 351. 


GENERAL INDEX. 


Where there are two or more entries after a name, the first (if the name is 
that of a mineral species) is the page on which the species is described, and a 
senicolon separates it from the fellowing entries. 


Aca'dialite, 323. 
Acan'thite, 131. 
Achre'matite, 168, 
Ac'mite, 268. 
Actin’olite, 271. | 
Actin'olyte, 488. 
Adamantine spar, 212. 
Ad'amite, 172. 
Adula’ria, Adular, 301. 
Aigirine, Aigyrite, 268. 
farinite, 337. 
Aaschy nite, 222. 
Agalmat olite, 326, 335, 474. 
Ag’ate, 256. 
Agric’olite = Eulytine, 278. 
Aikinite, 164, 
Ajkite, 349. 
Alaban’dite, 206. 
Alabas'ter, 229. 
Alas’kaite, 164, 165. 
Al'bertite, 349. 
Albite, 299; 45, 59. 
Alexandrite, 215. 
Algod’onite, 149. 
Alipite, 185. 
Allak'tite, 210. 
Allanite, 284. 
Altemontite, 113. 
Allopalladite, 142. 
Allophane, 318. _ 
Allophite, 339. 
Alluaudite, 209. 
Alluvium, 465. 
Almandin, Almandite, 279. 
Alshedite, 313. 
Altaite, 164. 
Alum, native, 217. 
Alum shale, 463. 
Alum stone, 217. 
Alu minite, 218. 
Aluminium, Compounds of, 211. 
fluorides, 216. 


32 


Al'unite, 217. 
Alu'nogen, 216, 
Alvite, 282. 
Amal'gam, 130. 
Amazonstone, 300. 
Amber, 348. 
Amblygonite, 218; 44, 
Amblystegite, 264; 456. 
Am'brite, 349. 
Amesite, 341. 
Amethyst, 255, 
Oriental, 212. 
Am’‘ian'thus, 271, 330. 
Ammo’nium alum, 217. 
Ammonium, Salts of, 249. 
Amphibole, 270. 
Amphib’olyte, 488. 
Am 'phigene, 295. 
Amphig'enyte, 479. 
Amyg'daloid, 485. 
Anal'cite, Analcime, 322. 
Anam 'esyte, 485, 
An’atase, 180. 
An'cramite, 175. 
Andalu’site, 306, 452, 456. 
An'desine, Andesite, 299. 
An‘desyte, 483. 
An'‘dradite, 279. 
An'drewsite, 203. 
An’'glesite, 165. 
Anhy'drite, 230. 
Animikite, 132. 
Ankerite, 289; 204. 
Annabergite, 184. 
Annerodite, 221. 
Annite, 291. 
Ano’mite, 291. 
Anor'thite, 298; 457. 
Anorthite rocks, 486. 
Anorthityte, 486. 
Anthophyl lite, 2738. 
An’'thracite, 351. 


498 GENERAL INDEX. 


Anthrac’onite, 237, 
Antig’orite, 330. 
Antillite, 331. 
Antimonate, Calcium, 234. 
Copper, 154. 
Lead, 168. 


Antimonial copper ores, 149, 150. 


lead ores, 167, 168. 
nickel ores, 183. 
silver ores, 182. 


Antimo’nite = Stibnite, 112. 


Antimony, Gray, 112. 
Native, 112. 
Red, 113. 
glance = Stibnite. 

Frees 321. 

Ap‘atite, 232; 47, 50, 455. 

Aphane’ ae 153. 

Aph’'rodite, 328, 

Aphrosiderite, 341. 

Aphthit'afite, 246. 

Apjohnite, 217. 

Aplome, 279. 

Ap'lyte, 471. 

Ahopht yllite, 316. 

Aquamarine, 274. 

Arag’onite, 237; 452. 

Arago'tite, 348, 

Arcanite, 246. 

Arctolite, 285. 

Arden’nite, 285. 

Arequi'pite, 168. 

Arfved'sonite, 2738. 

Argentane, 186. 

Argen'tine, 236. 

Argen’tite, 131. 

Argentopyrite, 131. 

Ar'gillyte, 463, 473. 

Argyropyrite, 181. 

Arite, 188. 

Arkansite, 180, 

Arkose, 462. 

Arksutite, 216. 

Arnimite, 153. 

Ar’querite, 130. 

Arrag’onite, 7. Aragonite. 

“Arsenate, Calcium, 234. 
Cobalt, 184.: 
Copper, 153. 

Tron, 2038. 
Lead, 167. 
Uranium, 188. 
Zinc, 172, 


Arsenic, Native, 110. 
White, 111. 
Arsenic group, 110. 
sulphide, 111. 
Arsenical antimony, 118. 
cobalt, 182. 
iron ore, 192, 193. 
_lead ores, 164. 
nickel, 182. 
Arseniosid’erite, 203. 
Arsen’olite, 111. 
Ar'senopy rite, 192. 
Asbestus, 266, 271, 330. 
Blue or Crocidolite, 273. 
Asbolan, Asbolite, 188, 208. 
Asmanite, 262. 
Asparagus stone, 233. 
Aspa’'siolite, 336. 
Asphal'’ tum, 349, 
Aspid ‘olite, 290. 
Astrak'anite 0. Blédite, 
Astrohpyllite, 292. 
Ataca'mite, 150. 
Atelestite, 114. 
Atelite, 151. 
Atopite, 234. 
Auerbachite, 282. 
Augite, 265; 442, 451. 
Augite- andesyte, 483. 
Augite-dioryte, 482; 483. 
Augite-granite, 478. 
Augite-syenyte, 478. 
Augitic trachyte, 475. 
Aurichalcite, 156, 173. 
Auriferous pyrite, 190, 
Auripigmentum, 111. 
Aurum musivum, 178, 
Autom 'olite, 214. 
Autunite, 188. 
Av'alite, 185. 
Aventurine quartz, 255, 
feldspar, 301. 
Ax'inite, 286. 
Az'urite, 156. 


Bab 'ingtonite, 268, 
Bagrationite v. Allanite, 
Baltimorite, 380. 
Balvraidite, 285. 
Ban‘atite, 481. 
Bar'cenite, 144, 


| Barite, 88, 240. 


Barium, Compounds of, 240. 


Bar’sowite, 298. 
Bar'ylite, 286. 
Bar'ytes, 240. 
Barytocalcite, 242. 
Baryturanite, 188. 
Basalt, 485. 
Ba’sanite, 257. 
Bastite, 331. 
Bastniisite, 223. 
Bathvillite, 249. 
Beaumontite; $26. 
Beauxite, 213. 
Beccarite, 281. 
Bechilite, 232. 
Bezecrite, 164. 
Belvraidite, 285. 
Benzole, 324. 


Bergamaskite, 272. 


Berthierite, 193. 
Bertrandite, 275. 
Beryl, 274. . 
Berzelianite, 149. 
Berzeliite; 934. 
Beyrichite, 181. 
Bieberite, 185. 
Biharite, 335. 
Bindheimite, 168. 
Binnite, 149. 
Biotite, 291. 
Bischofite, 224. 
Bismite, 114. 
Bismuth, 113. 
Bismuthinite, 114. 


Bismuth ores, 113, 114, 150. 


carbonate, 114, 
nickel, 183. 
silver, 129. 
telluride, 114. 
Bismutite, 114. 


Bismutoferrite, 278. 
Bismutospherite, 114. 
Bitter spar, v. Dolomite. 


Bitumen, 349. 
Elastic, 347. 


Bituminous coal, 350. 
Bituminous shale, 463. 


Bjelkite, 164. 

Black cobalt, 183. 
copper, 151. 
jack, 170. 
lead, 120. 
silver, 133, 

Blende, Sa 


GENERAL INDEX. 


Blédite, 225. 
Blomstrandite, 187. 
Bloodstone, 257. 
Blue iron earth, 202. 
copper, 147. 
vitriol, 152.. 
Bo'denite, 284.” 
Bog iron ore, 198. 
manganese, 207. 
Bole, 335. 
Bolivite, 114. 
Boltonite, 277. 
Boracic acid, 109; 
Boracite, 225. — 
Borate, Aluminium, 218, 
Ammonium, 250, 
Calcium, 231, 
Hydrogen, 109. 
Tron, 200 
Magnesium, 225. 
Sodium, 231. 
Bo'rax, 246. 
Bordosite, 180. 
Bor'nite, 148. 
Bo'rocal’ cite, 231. 
Boronatrocalcite, 231. 
Boron group, 109. 
Bort, 116. 
Bosjemanite, 217. 
Bot'ryogen, 200. 
Bot'ryolite, 311. 
Boulan’'gerite, 164. 
Bour’nonite, 149. 
Boussingaultite, 250. 
Bowenite, 331. 
Brackebuschite, 168. 
Bragite, 282. 
Branchite, 348. 
Bran 'disite, 342. 
Brass, composition of, 159. 
Braunite, 207. 
Bravaisite, 829. 
Breccia, 462, 
Brecbergite, 279. 
Breislakite, 271. 
Breithauptite, 183. 
Breunnerite, 226. 
Brewsterite, 326. 
Brittle silver ore, 133. 
Brochantite, 153. 
Bréggerite, 187. 


499 


Bromic silver, Bromargyrite, 184, 


‘ Bromlite, 242, 


500 GENERAL INDEX. 


Bromyrite (Bromic silver), 134, 


Brongniardite, 188; 164, 
Bronze, 159. 
Bronzite, 264. 
Brookite, 180. 
Brown coal, 351. 
hematite, 198. 
iron ore, 198. 
ochre, 181, 198, 
spar, 239. 
stone, 462. 
Brucite, 228. 
Brushite, 284. 
Buchol’zite, 307. 
Buchonite, 486. 
Bucklandite, 284. 
Buhrstone, 469. 
Bunsenine=Krennerite, 129, 
Bu'ratite, 173. 
Bytownite, 298. 


Cabrerite, 184. 

Cach' olong, 260. 
Cacox’enite, Cacoxene, 203, 
Cadmium, Ores of, 175, 
Cairngorm stone, 255, 
Caking coal, 351. 

Cal'aite, v. Callaite. 
Cal’amine, 174. 
Cal'ave'rite, 129. 

Calcite, 234; 51, 458, 455. 


Calcium, Compounds of, 227, 


Calc spar, 234 
Caled’onite, 166. 
Callai‘nite, 219. 
Callais, Callaite, 219, 
Cal'omel, 148. 
Ca'naanite, 461. 
Cancrinite, 294. 
Cannel coal, 351. 
Cantonite=Covellite, 147. 
Caoutchouc, Mineral, 34'7, 
Capillary pyrites, 181. 
Cappelenite, 275, 306. 
Carbonaceous shale, 463. 
Carbonado, 116. 
Carbonate, Calcium, 234, 
Carbonate, Bismuth, 114, 
Copper, 154, 156, 
Tron, 203. 
Lead, 168. 
Magnesium, 226. 
Manganese, 210. 


Carbonate, Sodium, 249, 
Strontium, 242. 
Uranium, 187, 
Yttrium, 223. 

Zine, 172. 

Carbonic acid, 120; 448. 

Carburetted hydrogen, 342, 

Carnal lite, 224. 

Carne’lian, 256. 

Car’ pholite, 318. 


_ Carrara marble, 433, — 


Carrollite, 181. 
Caryinite, 234. 
Cassinite, 302. 

Cassit’ erite, 176. 
Castor, Castorite, 270. 
Catapleiite, 317. 
Cataspi lite, 335, 
Cat'linite, 464. 
Cat’s-eye, 256. 
Celad'onite, 329. 
Celestialite, 349. 
Celes'tite, Celestine, 242, 
Cement stone, 236, 
Cerar’gyrite, 134, 


- Cerite, 318. 


Cerium ores, 221, 

Ce'rolite, 332. 

Cerus’site, 168. 

Cervan'tite, 113. 

Chab’azite, 322. 

Chalcan’'thite, 152, 

Chalced'ony, 255. 

Chal'cocite, 146. 

Chal'codite, 329. 

Chal'colite, 187. 

Chal'come'nite, 154. 

Chalcomorphite, 319, 

Chalcoph'anite, 208. 

Chalcophyl Tite, 154, 

Chalcopy rite, 147. 

Chalcosid’erite, 208. 

Chalcosine = Chalcocite, 146, 

Chalcosti'bite, 149. 

Chalcotri’chite = Capillary 
prite. 

Chalk, 236. 

Chal'ybite, 203. 

Chamasite, 189. 

Chathamite v. Chloanthite, 

Chen’evixite, 154, 

Chert, 256, 469. 

Chelmsfordite, 293. 


GENERAL INDEX. 


Chesterlite, 300. 
Chias'tolite, 307. 
Childrenite, 219. 
Chiolite, 216. 
Chiviatite, 149, 150. 
Chloanthite, 181. 
Chloraluminite, 216. 
Chlorastrolite, 317. 
Chloride, Ammonium, 249, 
Copper, 150. 
Lead, 165. 
Magnesium, 224. 
Mercury, 148. 
Potassium, 248. 
Silver, 134. 
Sodium, 243. 
eae Chlorite Group, 3387, 
9 


Chlorite schist, 489. 
Chlorite-argillyte, 489. 
Chloritoid, 341. 
Chlormagnesite, 224. 
Chlorocalcite, 229. 
Chloropal, 329. 
Chloropheeite, 340. 
Chlo’ rophane, 237. 
Chlo’rophy]'lite, 336. 
Chlorospinel, 214. 
Chlorothionite, 1538. 
Chlorotile, 154. 
Chodnefiite, 216. 
Chon'drodite, 303. 
Chon ’icrite, 338. 
Chromate, Lead, 166, 
Chrome yellow, 166. 
Chromic iron, 197. 
Chromite, 197. 
_ Chromium sulphide, 198. 
Chrysoberyl, 215. 
Chrysocolla, 157, 
Chrysolite, 277; 442, 449, 458, 456. 
Chrysolyte, 2. Peridotyte. 
Chrysoprase, 255 
Chrysotile, 330. 
Churchite, 222, 
Cimolite, 328. 
Cinnabar, 143. 
Cinnamon stone, 279. 
Cip’olin marble, 461, 
Citrine, 255. 
Clarite, 149. 
Claudetite, 111. 
Clausthalite, 164. 





Clay, 464. 


iron-stone, 198, 204. 
slate, 463. 


-Cleavelandite, 300. 


Cleiophane, 171. 
Cleveite, 187. | 
Clingmanite, 341, 


- Clinkstone, 479. 


Clinochlore, 340. 
Clinoclasite, 153. 
Clinochrocite, 200. 
Clinohumite, 304, 
Clinophalite, 200. 
Clintonite, 842. 
Coal, Mineral, 350, 
Brown, 351, 
Cannel, 351. 
Cobalt, Ores of, 180. 
Cobalt bloom, 184, 
glance, 181, 
pyrites, 181. 
vitriol, 185. 


- Cobaltite, Cobaltine, 182, 


Cobaltomenite, 184. 


- Coccolite, 266. 

| Coke, 352, 354. 

| Colemanite, 231. 

_ Collyrite, 318. 

— Coloph’onite, 279. 
- Colora’doite, 143. 


Columbite, 201. 


| Columbium, 202. 
| Comptonite, 320. 
| Confolensite, 329. 


Conglomerate, 461. 


- Conichalcite, 154. 
- Connellite, 49 (f. 11), 153, 
_ Cookeite, 335. 


Copal, Mineral, 349. 
Copaline, Copalite, 349, 
Copi'apite, 200. 
Copper, Ores of, 145. 
Copper, Native, 145. 
Black, 151. 
froth, 154. 
glance, 146. 
Gray, 150. 
mica, 154. 
nickel, 182, 
pitas 147. 


silicate, “ise, 157, 
vitriol, 152. 


501 


502. GENERAL INDEX: 


Copperas, 199. 
Coprolites, 2338. 
Coquim’bite, 200. 
Coracite, 187. 
Cor'dierite, 287. 
Corneous lead, 169. 
Cornwallite, 154. 
Coronguite, 168. 
Corsyte, 486, 
Corun’dellite, 341. 
Corundoph’ ilite, 341. 
Corundum, O11. 
Co’salite, 164. 
Cossaite, 299. 
Cotun'nite, 165. 
Covel'lite, Covelline, 147. 
Crednerite, 207. 
Crocidolite, 278. 
Cro'coite, Crocoisite, 166. 
Cron’stedtite, 341. 
Crooke'site, 149. 
Cry‘olite, 216. 
Cry'ophyl'lite, 290. 
Cryptohalite, 250. 
Cryptolite, 222. 
Cryp'tomor’phite, 2381. 
Cu banite, 148. 

Cube ore, 208. 
Culsageeite, 339. 
Cummingtonite, 272. 
Cu'prite, 151. 
Cuproschcelite, 282. 
Cuprotungstite, 153. 
Cuspidite, 277. 
Cyanite, 808; 457. 
Cyanotrichite, 153. 
Cymat olite, 269. 
Cyprine, 282. 


Dacyte, 483. - . 
Daleminzite, 131. 

Dam 'ourite, 290, 335. 
Damourite schist, 473. 
Da‘naite, 193. 
Danalite, 278. 
Danburite, 286. 


Darwinite= Whitneyite, 149. 


Datholite, Datolite, 311. 
Daubréelite, 198. 
Daubréite, 114. 

* Davreuxite, 308. 
Davyne, 294. 
Dawsonite, 220, 


Dechenite, 168. 
Degcrdoite, 338. 
Delanouite, 329. 
Delawarite, 302. 
Delessite, 340.. 
Delvauxite=Dufrenite. 
Dendrites, 638,. 449. 
Derbyshire spar, 228. 
Descloi zite, 168. 
Desmine, 325. 
Destinegite, 203. 
Detritus, 465... 
Dew eylite, 332. 
Diabantachronyn, 340. 
Diaban tite, 340. 
Di'abase, 445, 485. 
Diaclasite, 264. 
Diadelphite, 210. 
Di'allage, Green, 267. 
Dial'logite= Rhodochrosite, 210, 
Diamond, 115. 
Diaphorite, 134. 
Di'aspore, 213. ) 
Diatomite, Diatom e rth! 261, 466. 
Di'chroite, 287. 
Dickinsonite, 209. 
Didymium ores, 222, 228. 
Dietrichite, 217. 
Dihy’'drite, 154. 
Dinite, 348. 
Diopside, 266. 
Dioptase, 156; 278. 
Di'oryte, 481. 
Dioryte schist, 481. 
Orbicular, 486. 
Diphanite, 347, 
Dipyre, 293. 
Dister'rite, 342, 
Disthence, 308. 
Ditroyte, 479. 
Dog-tooth Spar, 235, 
Doleroph’ anite, 152. 
Dol'eryte, 484; 442, 445, 
Dolomite, 238: 455. 
Dol’ omyte, 458, 460. 
Domey’ kite, 149, 
Do'myte, AT5. 
Dopplerite, 349. 
Dree'lite, 241. 
Dudleyite, 341. 
Du frenite, 203. 
Du'frenoy'site, 164, . 
Dumortierite, 308... 


GENERAL INDEX. 


Dumreicherite, 217. 
Du'nyte, 489. 
Durangite, 219. 
Dirfeldtite, 164. 
Dutch white, 241. 
Duxite, 349. — 
Dysanalyte, 234; 222. 
Dys'crasite, 182. 
Dysluite, 215. 
Dysodile, 349. 

Dysyn tribite, 335, 474. 


Ecdemite, 167. 
Eclogyte, 487. 
Edel forsite, 265. 
Ei denite, 273. 
Ed'ingtonite, 318. 
Edmonsonite, 189. 
Edwardsite=Monazite. 
Eggonite, 175. 
Ehlite, 154. 
Ekebergite, 293. 
Ekmannite, 338. 
Ele ’olite, 293. 
Elat’erite, 347. 
Electro-silicon, 261, 466. 
Electrum, 123. 
Eliasite, 187. 
El pasolite, 216. 
Em ‘bolite, 134. 
Emerald, 274. 
Oriental, 212. 
Emerald-nickel, 185. 
Emery, 211. 
Emerylite, 341. 
Emmonsite, 203. 
Emplectite, 149. 
Empholite, 308. 
Enar'gite, 149. 


Enceladite, v. Warwickite. 


Endlichite, 167. 
Enstatite, 264; 456. 
Eos'phorite, 220. 
Eozooin, 331. 
Epichlorite, 328. 

_ Epidosyte, 488. 
Epidioryte, 482. 
Ep idote, 283; 457. 

Epistil’bite, 326. 


Epsom salt, Epsomite, 224. 


Erbium ores, 222. 
Erdman'nite, 318. 
Er'‘inite, 153. 


Eriochalcite, 151. 
Erubescite, 148. 
Er’ythrite, 184. 
Erythrosiderite, 193. 
Erythrozincite, 171. 
Esmarkite, 336. 
Essonite, 279. 
Ettringite, 231. 
Eucairite, 182; 149. 
Euchlorite, 291. 

Eu 'chroite, 153. 
Euclase, 311. 
Eucolite, 275. 


| Eucrasite, 318. 


Eucryptite, 294. 
Eucryte, 486. 
Eudyalite, Eudi’alyte, 275, 
Eudnophite, 322. 
Eukairite, v7. Eucairite. 
EKulysyte, 453. 
Eulytite, Eulytine, 278. 
Euosmite, 349. 
Eu'photide, 487. 
Euphyllite, 335. 
Eupyr'chroite, 2338, 
Euralite, 340. 

Euryte, 474. 
EKusynchite, 168. 
Eux’enite, 222, 
Evansite, 219. 
Evigtokite, 216. 


Fahlerz, 150. 
Fahlunite, 336. 
Fairfieldite, 209. 
Famatinite, 149. 
Faroéelite, 320. 
Fassa'ite, 266. 
Fau'jasite, 322. 
Fa'yalite, 277. 
Feather ore, 164. 
Feldspar Group, 296. 
Felsite, 302. 
Felspar, v. Feldspar, 296. 
Felsyte, 474. 
Ferberite, 200. 
Fergusonite, 221. 
Ferrotelluride, 193. 
Fibroferrite, 200. 
Fibrolite, 307; 456. 
Fichtelite, 348, 
Fillowite, 210. 
Fiorite, 261. 


503 


504 GENERAL INDEX. 


Fioryte, 469. 

Fireblende = Pyrostilpnite. 

Fire-marble, 431. 

Fischerite, 919. 

Fléches damour, 180, 258. 

Flint, 256, 469. 

Float-stone, 261. 

Flos ferri, 238. 

Fluel’lite; 216. 

Fluidal texture, 444. 

Fluocerine, 221. 

Fluocerite, 221. 

Fluor, Fluorite, 22%. 

Fluor spar, 227. 

Fluorides, Aluminium, 216. 
Calcium, 227. 

Folliated tellurium, 164. 


Fontainebleau limestone, 236. 


Foresite, 325. 
Forsterite, 277. 
Fowlerite, 268. 
Foyayte, 479. 
Franklandite, 231. 
Franklinite, 197. 
Fredericite, 149. 


Free-stone, Brown-stone, 462. 


Frei'bergite, 150. 
Frei’esleb’enite, 133. 
French chalk, 326, 490. 
Fren’zelite, 114. 
Freyalite, 318. 
Frie'delite, 278. 
Frieseite, 181. 
Frigidite, 150. 


Gabbro, 484, 487. 
Gadol'inite, 284. 
Gagates, 352. 
Gah'nite, 214. 
Gale’na, Gale’nite, 160. 
Galenobismutite, 164. 
Galmei, 174. 
Ganomalite, 169. 
Garnet, 278; 449, 455. 
rock, 487. 
Garnetyte, 487. 
Garnierite, 185. 
Gas, Natural, 342, 
Gastal'dite, 273. 
Gay-Lussite, 249. 
Gearksutite, 216. 
Gedanite, 349, 
Gehlenite, 306. 


Genth’ite, 185, 382. 
Geoc’erite, 349. 
Geoc’ronite, 164, 
Geodes, 66. 
Geomyricite, 349, 
Gerhardtite, 154. 
Gersdorflite, 183. 
Gey’serite, 261, 469. 
Gibbsite, 213. 
Gie’seckite, 298, 334, 474. 
Gigan'tolite, 335, 386. 
Gillingite, 338. 
Girasol, 260. 
Gismon‘dite, Gismondine, 3818. 
Glagerite, 335. 
Glaserite, v. Arcanite, 246. 
Glass, 441, 454, 476. 
Glauber salt, 246. 
Glau'berite, 246. 
Glau’codot = Cobaltic Arseno 
pyrite. 
Glau'colite, 293, 
Glau'conite, 329; 464, 
Glau‘cophane, 273. 
Glaucophanyte, 489. 
Globulites, 442, 
Gme'linite, 323. 
Gneiss (pron. like nice), 471. 
Gold, 122. 
Gos'larite, 172. 
Gothite, 199. 
Goyazite, 219. 
Grahamite, 349. 
Gramenite, 329. 
Grammatite, 270. 
Granite, 470. 
mica-less, 471, 
Granityte, 470, 
Granular quartz, 468. 
Granulyte, 471. 
Graphic granite, 471. 
tellurium, 132; 129, 
Graphite, 119. 
Grastite, 340. 
Gray antimony, 112. 
copper, 150. 
Gray-wacke, Grau-wacke, 463, 
Green sand, 464. 
Greenockite, 175. 
Greenovite, 812. 
Greenstone, 481, 482. 
Greisen, 472. 
Grindstones, 463. 


GENERAL INDEX. 505 


Grit, 462. 
Grochauite, 341. 
Groddeckite, 323. 
Groppite, 335. 
Grossularite, 279. 
Grothite, v. Titanite, 312. 
Griinauite, 183. 
Guadalcazarite, 148. 
Guanajuatite, 114. 
Guano, 233. 
Guarinite, 318. 
Guayac'anite, 149. 
Gueja rite, 149. 
Gui'terman’ite, 164. 
Giimberlite, 335. 
Gummite, 187. 
Gurho’fite, 239. 
Guyaquillite, 349, 
Gymuite, 332. 
Gypsum, 229. 
Gyrolite, 315. 


Hai'dingerite, 234. 
Hair-salt, 224. 
Ha'lite, 243. 

Hal'lite, 339. 
Halloy'site, 335. 
Halotrichite, 200, 217. 
Hamartite = Bastnisite, 223. 
Hanksite, 249. 
Hannayite, 250. 
Harmotome, 323. 
Harringtonite, 321. 
Har’ risite, 147. 
Hartite, 348. 


Hatch’ettite, Hatchettine, 347. 


Hatchet’tolite, 187. 
Hauerite, 206. 
Haughtonite, 291, 
Hausman’nite, 207. 
Haiiyne, 294. 
Haiiynite, 294. 
Hauyn'ophyre, 480. 
Haydenite, 323. 
Hayesine, 282. 
Heavy spar, 240. 
He'bronite, 218. 
Hed'enber'gite, 267. 
Hed'yphane, 167. 
Heldburgite, 282. 
He'liotrope, 257. 
Helminthe, 340. 
Helvite, Helvin, 278, 


Hemafibrite, 210. 
Hematite, 193. 
Brown, 198. 
Red, 193. 
Hemidioryte, 480. 
Hemithrene, 482. 
Henwoodite, 220. 
Hercynite, 215. 
Herderite, 234. 
Herrengrundite, 153. 
Herschelite, 323. 
Hessite, 131. 
Hetzrolite, 207. 
Heterogenite, 184. 
Heter’osite, 209. 
Heubachite, 184. 
Heu'landite, 325. 
Hid'denite, 269. 
Hieratite, 262. 
Hisingerite, 338. 
Heernesite, 226. 
Hofman nite, 349. 
Homilite, 312. 
Honey-stone, 220. 
Hopeite, 172. 
Hornblende, 270; 442, 451, 456. 
schist, 446, 488. 
Hornblende- granite, A477, 
Hornblende- -picryte, 489. 
Hornblendyte, 488. 
Horn quicksilver, 143. 
silver, 134. 
Hornstone, 256, 469. 
Horse-flesh ore, 149. 
Horton’olite, 277. 
Houghite, 213. 
Howlite, 282. 
Huantajayite, 244. 
Huascolite, 171. 
Hiib’nerite, 200. 
Hudsonite, 267. 
Hullite, 388. 
Humboldtilite, 283. 
Humboldtine, 204. 
Humboldtite, 311. 
Humite, 303, 304. 
Huntilite, 132. 
Hureaulite, 209. 
Hyacinth, 281, 306. 
Hyalite, 261. 
Hyalomelan, 485. 
Hyalomicte, 472. 
Hyal’ophane, 299. 


506. GENERAL INDEX. 


Hyalosid’erite, 277. 
Hyalotecite, 169. 
Hydrar’gillite, 213. 


Hydraulic limestone, 286, 459. 


Jiydrobo’racite, 282. 


Hydrocarbons, 842, 344, 348. 


Hydrocastorite, 270. 
Hydrocerussite, 169. 
Hydrochloric acid, 251. 
Hydrocy’anite, 153. 
Hydrodol’omite, 239. 
Hydrofluorite, 251. 
Hydrofranklinite, 172. 
Hy’drogen, 251. 
Hy'drogio’bertite, 226. 
Hydromag'nesite, 224, 226. 
Hy'dro-mi'ca Group, 835. 
Hydromi’ca schist, 473. 
Hydroneph’elite, 321. 
Hydrophane, 260. 
Hydroph’ilite, 229. 
Hydrophite, 332. 
Hydro-rho'donite, 268, 
Hydrotalcite, 213. 
Hydrozincite, 173. 
Hygroph’ilite, 290. 
Hypersthene, 264; 456. 
Hypersthene-andesyte, 484. 
Hypersthene-dioryte, 482. 
Hypersthene-gabbro, 484, 
Hypersthenyte, 484, 
Hy’peryte, 484. 
Hystatite = Menaccanite. 


Ib’erite, 835, 836. 


Ice, crystallization of, 4, 251. 


Iceland spar, 235. 
Ice Stone, 216. _. 
I'docrase, 282. - 
Id’rialine, Idrialite, 348. 
Iglestrémite, 224, 277. 
Ihleite, 200. “3 
Tlesite, 208. 
Il'menite, 195. 
Il'vaite, 285. 
Indianite, 298. 
Indicolite, 805. 
Infusorial earth, 261, 465, 
l’odar’gyrite, 184. 
Iodide, Mercury, 144. 
Silver, 134. 
fodobromite, 1384. 
lod'yrite, 1384. 


| Yolite, 287. 


Hydrous, 287, 336. 
To'nite, 349. 
Ir'idos’mine, 141. 

Iron, Ores of, 188. 
Magnetic, 196. 
Native, 189. 
pyrites, 189. 
sinter, 208. 
Titanic, 195. 

Tronstone, Clay, 194. 

I'serine = Menaccanite, 195. 

Isocla'site, 154. 

Itab'yrite, 4738. 

Itacol’umyte, 468. 


-Itt’nerite, 294. 
Ix’olyte, 348. 


Jacobsite, 197. 
Jade, 271. 


‘ Jadeite, 271. 
‘Jalpaite, 131. 


Jamesonite, 164, 
Jargon, 281. . 


_Jar’osite, 200. 
‘Jasper, 257. 


rock, 469. 


_Jaspery clay iron-stone, 194, 
._ Jefferisite, 339. 


Jeffersonite, 267. 
Jelletite, 279. 


' Jenkinsite, 332. 


Jenzschite, 262. 


' Jeremejefiite, 218. — 
‘Jet, 352. 


Johannite, 188. 


: Jollyte, 338. 
_Joseite, 114. 


(K: for some words with an 
initial K, see under C.) 


- Kainite, 225. 


Kainosite, 318. 
Kalinite, 217. 


_Kaluszite = Syngenite. 
‘Kimmererite, 389. 


Kaneite, 206. 


‘Kaolin, Kaolinite, 882; 464, 
‘Karyinite, 167. 
‘Keatingine, 268. 


Keilhauite, 313. - 


‘Kentrolite, 169. 
-Ker’mesite, 113. 


- 


GENERAL INDEX. 507 


Kerrite, 389. 
Kersanton, Kersantyte, 480. 
Kieserite, 225. 
Killi’nite, 334. 
Kjerulfine, 226. 
Kneb’elite, 277. 
Ko'bellite, 164. 
2<o'chelite, 221. 
Kongsbergite, 130. 
Konigite, Kénigine, 153. 
Ko’ninckite, 208. 
K6nlite, 3848. 
Koppite, 221. 
Kotschubeite, 340. 
Kéttigite, 172; 184. 
Krantzite, 349. 
Kreittonite, 215. 
Krem‘ersite, 193. 
Krennerite, 129. 
Krisu’vigite, 153. 
Kroénkite, 153. 
Kru'gite, 225. 
Kupfferite, 278. 
Ky‘anite, 308; 457. 


Lab'radi’oryte, 482. 
Labradorite, 298; 442, 457. 
Labradorite-dioryte, 482. 
Lag’onite, 200. 
Lampadite, 208. 
Lan’arkite, 166. 
Langite, 153. 

Lanthanite, 223. 
Lanthanum ores, 221. 
Lapis-lazull, 295. 

Lapis ollaris, 326. 
Larderellite, 250. 


Laumontite, Laumonite, 315. 


Laurite, 141. 
Lautite, 149, 
Lawrencite, 193. 
Laz’ulite, 218. 
Lead, Ores of, 160. 
Leadhillite, 166. 
Lecont'ite, 250. 
Ledererite, 323. 
Led’erite, 313. 
Lehrbachite, 164. 
Lehuntite = Natrolite, 321. 
Leidyite, 317. 
Lennilite, 302. 
Lenz’inite, 335. 
Leonhardite, 316. 


Lepidok’rokite, 199. 
Lepid’olite, 289. 
Lepidom’elane, 291. 
Leptinyte, v. Granulyte. 
Lettsomite = Cyanotrichite, 153. 
Leuchtenbergite, 340. 
Leucite, 295; 455. 
Leucite. Rocks, 479. 
Leuco-tephrite, 480. 
Leucitophyre, 479, 
Leucityte, 480. 
Leucochalcite, 154. 
Leucomanganite, 209. 
Leucotile, 319. 
Leucoph’'anite, 277. 
Leucopyrite, 193. 
Leu’'coxene, 312, 453. 
Levyne, Levynite, 323. 
Lher’zolyte, 488. 
Libeth’enite, 154. 
Lie’bigite, 188. 
Lie'vrite = -Ilvaite, 285. 
Lignite, 351. 
Lillite, 338. 
Limbachite, 332. 
Limburgyte, 488. 
Limestone, 235, 457, 460. 
Hydraulic, 459. 
Limnite, 199. 
Li’monite, 198. 
Linarite, 166. 
Lindackerite, 185. 
Linne’ite, 181. 
Lionite, 108. 
Lip’aryte, 476. 
Liroco’nite, 153. 
Liskeardite, 220. 
Listwianyte, 489. 
Lithioplilite, 209. 
Lithioph’orite, 207. 
Lithographic stone, 459. 
Lith’omarge, 335. 
Liver ore, 143. 
Livingstonite, 113. 
Lodestone, 197. 
Leess, Loss, 465. 
Lo'ganite, 339. 
L6l'lingite, 193. 
Lophoite, 340. 
Lovenite, 282, 
Liweite, 225. 
Lowigite, 217. 
Lox’oclase, 301. 


508 GENERAL INDEX. 


Luckite, 200. 

Ludlamite, 203. 
Ludwigite, 225. 
Lumachelle, 459, 
Liineburgite, 226. 
Luzonite, v. Enargite. 
Lydian stone, Lydite, 257. 
Lyncurium, 306, 


Mac'le, 305. 
Macfarlanite, 182. 
Maconite, 889. 
Magneferrite, 224, 
Magnesite, 226. 


Magnesium, Compounds of, 223. 


Magnetic iron ore, 196. 
pyrites, 192. 
Mag'netite, 196; 31, 455. 
Magnoferrite, 204, 
Mag’nolite, 144. 
Mal'achite, Blue, 156. 
Green, 154. 
Malac’olite, 266. 
Mal‘acon, 282. 
Maldonite, 123. 
Malinowskite, 150. 
Mallar'dite, 208. 
Manganblende, 206. 
Manganbrucite, 224. 
Manganepidote = Piedmontite, 
284. 


Manganese ores, 206. 
Manganese spar, 268. 
Manganhedenbergite, 267, 
Man's ganite, 207. 
Manganosite, 206. 
Manganostibite, 206. 
Mangantantalite, 202. 
Marble, 235, 459, 460. 
Mar’casite, 191. 

Marekanite, 2. Pearlyte. 
May’ garite, B41, 

Margar’odite, 290, 3385. 
Margarophy lite Section, 826. 
Mar’ ialite, 298. 

Marl, 460. 

Marmatite = ferriferous Blende. 
Mar’ molite, 330. 

Marsh gas, 342. 

Martite, 194. 

Mascagnite, Mascagnine, 250. 
Masonite, 341. ' 
Matlockite, 165. 


Matricite, 318. 

Maxite, 166. 
Medjidite, 188. 
Meer’schaum, 822. 
Mei'onite, 293. 
Melac’onite, 151. 
Mel’anite, 279. 
Melanochroite, 166. 
Melan’olitey 838. 
Melanophlo’gite, 262. 
Melanosiderite, 199. 
Melanotecite; 169. 
Melanothal’lite, 151. 
Melan'terite, 199. 
Mel'aphyre, 483, 485. 
Mel'ilite, Mel’lilite, 283. 
Melilite-basalt. 486. 
Meliph'anite, Melin’ophane, 277. 
Mellite, 220. 

Me’ lonite, 183. 
Menac’canite, 195; 455. 
Men'dipite, 165. 
Mendozite, 217. 
Meneghi'nite, 164, 
Menilite, 261. 

Mercury, Ores of, 142. 
Meroxene, 291, 457. 
Mes'itine, Mes’‘itite, 204. 
Mesole, 320. 

Mesolite, 321. 
Mes‘otype = Natrolite, 
Metabrushite, 234. 
Metachlorite; 319. 
Metacinnabarite, 148. 
Metax’ite, 320. 
Metaxoite, 338. 
Meymacite, 109. 
Miar'gyrite, 133. 
Miar‘olyte, 470. 
Mias'cyte, 479. 

Mica, Mica Group, 987; 457, 
hydrous, 335. 
Mica-dioryte, 480, 482. 
Mica-porphyrite, 480. 

Mica schist, 473. 
Mica- Arachyte, 475. 
Michaelsonite, 284. 
Mic’rocline, 300. 
Microgranite, 470. 
Micropegmatite, 471. 
Mic’rolite, 234; 222. 
Microlites, 441. 
Mic’rosom'mite, 294. 


GENERAL INDEX. 


Middletonite, 349. 
Milarite, 278. 
Millerite, 181. 
Millstone grit, 426, 
Mim’etene, Mimetite, 167. 
Mineral coal, 850, 

oil, 344. 

~ pitch, 349. 

Minette, 473. 
Minium, 165. 
Mirab’ilite, 246. 
Mise’nite, 246. 
Mispickel, 192. 
Mixite, 154. 
Mizzonite, 293. 
Mocha stone, 256. 
Molybdate, Lead, 166. 
Molyb’denite, 108. 
Molybdite = yellow oxide, 109. 
Molybdomenite, 168. 
Molysite, 193. 
Mon’azite, 222. 
Monetite, 234. 
Monimolite, 168. 
Monite, 234. 
Mon’radite, 317. 
Mon’'tanite, 114. 
Montebrasite, 218. 
Mon’ ticel‘lite, 277. 
Montmartite, v. Gypsum. 
Montmorillonite, 329, 
Moonstone, 299, 301. 
Mordenite, 326. 
Morenosite, 185. 
Moronolite = Jarosite, 200. 
Mor'venite, 324. . 
Mosaic gold, 178. 
Mosan’drite, 285. - 
Moss agate, 256. 
Mottrammite, 168; 154. 
Mountain cork, 271. 

leather, 271, 

tallow, 347. 
Muller’s glass, 261, 
Mundic, 191. 
Muriatic acid, 251. 
Muromontite, 284. 
Mus'covite, 288. 
Muscovy glass, 289. 


Nadorite, 168. 
Nagyagite, 164; 129. 
Naphtha, 345. 


509 
Naphthalin, 348. 
Navt'rolite, 321. 
Natron, 249. 
Nauman’nite, 181. 
Nec’ronite, 302. 
Needle ore, 164. 
Nefdanskite, 141. 
Neft-gil, 347. 
Ne’mualite, 228. 
Ne'ochry'solite, 277, 
Neocianite, 157. 
Neot’ocite, 338. 
Nepheline-doleryte, 486. 
Nepheline-tephryte, 486. 
Neph’'elinyte, 486. 
Neph’elite, Nepheline, 298; 455. 
Nephelite rocks, 478, 486. 
Neph’rite, 271. 
Neudortfite, 349. 
Nevadite, 476. 
Newberyite, 226. 
Nic’colite, 182. 
Nickel-gymnite, 332. 
Nickel, Ores of, 180. 
stibine, 183. 
vitriol, 185. 
Ni’grine, 179. 
Niobite = Columbite, 201. 
Niobium, Compounds of, 201. 
Nitrate, Calcium, 234. 
Potassium, 247, 
Sodium, 248. 
Nitratine, 248. 
Nitre, 247. 
Nitrobarite, 242. 
Nitrocalcite, 234. 
Nitromagnesite, 226. 
No’cerine, 224. 
Nohlite, 221. 
Nontronite, 829. 
Noryte, 484. 
Nosean, Nosite, 294. 
Noumeite, 185. 
Novac'ulyte, 468. 
Nut’'talite, 293. 


Obsidian, 476; 442. 
Ochre, Brown, 198. 
Red, 194. 
Yellow, 198. 
Octahe'drite, 180. 
C£llach’erite, 290. 
CErstedite, 282. 


510 GENERAL INDEX. 


Ogcoite, 340. 
O’kenite, 315. 

Oil, Mineral, 344, 
Oktib’behite, 189. 
Olafite = Albite. 
Ol'igoclase, 299; 457. 
Oliv’enite, 153. 


Ol'ivine, 277; 456; v. Chrysolite. 


Olivine-gabbro, 484, 
Omphacite, 487, 
Onofrite, 148. 
Onta’riolite, 293. 
Onyx, 256. 

Odlite, 236. 

Opal, 259; 454. 
Opal Jasper, 261. 
O’phicalce, 490. 
O'phiolite, 330. 
Ophiolyte, 490. 
O'phyte, 482. 
Or’angite, 318. 
Orileyite, 193. 
Or'piment, 111. 
Or'thite, 284. 
Orth’oclase, 300; 442, 456. 
Ortholyte, 4738. 
Oryzite, 326. 
Osteolite, 288. 
Ot'trelite, 341. 
Ouvar'ovite, 280. 
Ozar'kite, 820. 
Ozoc’erite, Ozokerite, 347. 


Pach 'nolite, 216. 
Packfong, 186. 
Pago'dite, 335. 
Palag’onite, 335. 
Palatinite, 485. 
Palla’dium, 141. 
Pandermite, 281. 
Paraffin, 347. 
Paragonite, 290. 
schist, 474. 
Parank’erite, 239. 
Paranthine, 293. 
Parastil'bite, 826. 
Par’ gasite, 272. 
Parisite, 223. 
Par’ophite, 335. 
Parophite schist, 473. 
Partzite, 154. 
Pattersonite, 341. 


Paulite = Hypersthene, 264. 


Pealite, v. Geyserite. © 
Pearl sinter, 261, 469. 
Pearl spar, 239. 
Pearlstone, Pearlyte, 442, 476. 
Peat, 352. 

Peck'hamite, 278. 
Pectolite, 315. 

Peganite, 219. 
Pegmatolite, ». Orthoclase. 
Pegmatyte, 470, 471. 
Pelagite, 207. 

Pelhamite, 331. 
Pencil-stone, 828. 
Pennine, Penninite, 339. 
Pennite, 239. 

Peperino, 464. 

Per'iclase, Periclasite, 2238. 
Peridot, 277. 

Peridotyte, 489. 
Perof'skite, Perowskit, 180. 
Pet’alite, 269. 

Petro’leum, 344. 
Petrosi'lex, 474. 

Petrified wood, 258. 
Petuntze, 334. 

Petzite, 182; 129. ° 
Phac’olite, 323. 
Pharmac’olite, 234. 

Phar’ macosid’erite, 208. 
Phen'acite, 275. 

Phengite, 289. 
Philadelphite, 339, 
Philippite, 153. 
Phillipsite, 324. 
Phlog'opite, 290. 
Pheenicochroite, 166. 
Phol’erite, 335. 
Phon’'olyte, 479. 
Phos’genite, 169. 


-Phosphate,. Aluminium, 218, 


Ammonium, 250, 
Calcium, 232, 234, 
Cerium, 222. 
Copper, 153. 
Tron, 202. 
Lead, 167. 
Manganese, 208. 
Uranium, 187. 
Yttrium, 222, 
Phos’phoce’rite, 228. 
Phosphochalcite, 154, 
Phosphochro’mite, 168. 


_Phosphorite, 233, 


GENERAL INDEX. 511 


Phosphuranylite, 188, 
Phthanyte, 469. 
Phyllite, 341. 
Phyllyte, 463. 
Physalite, 309. 
Phytocollite, 349. 
Picite, 203. ; 
Pick’eringite, 217. 
Pic’otite, 214.. 
Picrallumogen, 218. 
Picroepidote, 284. 
Pic’rolite, 330. 
Picrom’crite, 225. 
Pic’rophyll, 317. 
Pic’rosmine, 317. 
Pic'ryte, 488. 
Piedmon’tite, 284, 
Pilarite, 157. 
Pilinite, 318. 
Pilolite, 317. 
Pimelite, 185. 
Pinguite, 329. 
Pi'nite, 334; 474, 
Pi'nitoid, 335. 
Pinnoite, 225. 
Pinolite = Magnesite. 
Pipe-clay, 464. 
Pisanite, 200. 
Pi'solite, 236. 
Pis'tacite, 284. 
Pitchblende, 186. 
Pitchstone, 476; 442. 
Pitkarandite, 317. 


Pitticite = Iron Sinter, 203. 


Plagiocitrite, .217. 
Plag’ioclase, 296. 
Plag'ionite, 164. 
Plasma, 257, 

Plaster of Paris, 230. 
Plat'iniridium, 141. 
Plat‘inum, Native, 139. 
Ple’onaste, 214. 
Plessite = Gersdorflite, 183. 
Plumba’go, 119. . 
Plumbic ochre, 165. 
Plumbogummite, 165. 
Plumbostan’nite, 164. 


Polianite = Pyrolusite, 206. 


Polishing powder, 466. 
Pol'lucite, 275. 
Pollux, 275. 
Pol'yar 'gite, 335. 
Pol’yar’gyrite, 133. . 


Polyar’senite, 210. 
Pol'ybasite, 133; 149. 
Pol! yerase, 222. 
Polyd’ ymite, 181. 
Pol'yhal'ite, 225. 
Polylite, 267. 
Polylith'ionite, 290. 
Pol'ymig'nite, 222 
Porcelain jasper, ANB. 
Porcel'anyte, 475. 
Porcel’lophite, 330. 
Porfido verde antico, 452. 
Por'pezite, 142. 
Por’phyrite, 481. 
Porphyritic-structure, 440. 
Porphy roid, 472. 
Por'phyry, 440, 474. 
Antique green, 440, 485. 
Antique red, 440, 481. 
Felsyte, 474. 
Globular; 474. 
Portland cement, 461. 
Portor, 458. 
Potassium. Compounds of, 248, 
Potstone, 826. 
Potter’s clay, 464, 
Poz'zuola‘na, 464. 
Prase, 255. 
Pregrat'tite, 290. 
Prehn’‘ite, 317. 
Priceite, 231. 
Prochlorite, 340. 
Proid’onite, 262. 
Propylyte, 483. 
Prosepnite, 347. 
Pros’opite, 216. 
Protobastite v. Bronzite, 264. 
Protogine, 472. 
Protovermiculite, 339. 
Proustite, 133. 
Przi'bramite, 175. 
Psammite v. Sandstone, 
Pseudobrookite, 180. 
Pseudomalachite, 154, 
Pseudonatrolite, 321. 
Pseud’ophite, 339. 
Pseudosmaragdite, 274. 
Pseudotriplite. 209. 
Psilom’elane, 207. 
Psittac’inite, 169; 154. 
Pterolite, ». Lepidomelane. 
Pucherite, 114. 


.Pudding-granite, 470. - 


512 


Pudding-stone, 462. 

Pumice, 476. _ 

Purple copper = Bornite, 148, 
Pycnite, 309. 

Pyral'lolite, 817; 827. 
Pyrar’gillite, 336, 
Pyrar’gyrite, 182. 

Pyrene'ite, 279. 

Pyrite, 189; 5, 6, 80, 455. 
Pyri'tes, Arsenical, 192. 
Auriferous, 190. 
Capillary, 181. 
Cobalt, 181. 
Cockscomb, 191. 

Copper, 147, 148. 

Hepatic, 191, 

Tron, 189. 

Magnetic, 192. 

Radiated, 191. 

Spear, 191. 

White iron, 191. 
Py’roau'rite, 224. 
Py'rochlore, 234; 222. 
Py'rochro'ite, 207. 
Py'rolu’site, 206. 
Pyromeride, 474. 
Py’romor'phite, 167. 
Py’rope, 279. 
Py'rophos’phorite, 234, 
Py’rophyl’lite, 328. 

slate, 490. 
Py’ropbyl'lyte, 490. 
Py'rophy’salite, 309, 
Py’roscle'rite, 338. 
Pyros'malite, 318. 
Pyrostibite = Kermesite, 1138. 
Py'rostilp’nite, 134. 
Py'roxene, 265; 453, 456. 
Pyrox’enyte, 488. 
Pyr’rhosid’erite, 199. 
Pyr'rhotite, 192. 


Quartz, 258; 55, 56, 442, 451, 
455 


Granular, 468. 
Quartzyie, 468. 
Quartz-dioryte, 481. 
Quartz-porphyry, 470, 471, 472, 

474, 476, 483, 485. 

Quartz-trachyte, 476. 
Quartz-syenyte, 477, 
Quicklime, 235. 
Quicksilver, 142, 


GENERAL INDEX, 


Rai'mondite, 200. 
Ralstonite, 216, 
Randite, 188. 
Rath’olite, 315, 
Rau’ite, 335. 
Realgar, 111. 


Red antimony, 113, 


chalk, 194. 
copper ore, 151. 
hematite, 194, 
lead, 165. 
ochre, 194. 
silver ore 182, 188. 
zinc ore, 171. 
Reddingite, 209. - 
Redruth’'ite, 146. 
Refdanskite, 330, 
Reichardtite, 224, 
Reinite, 201. 
Reissite, 326. 
Rem'ingtonite, 185. 
Rens’selaerite, 326, 490, 
Restor’melite, 335. 
Retin‘alite, 380. 
Retinite, 476. 
Retzbanyite, 164. 
Rhab’dophane, 228, 
Rhee’ tizite, 309. 
Rhagite, 114. 
Rhodium gold, 128. 
Rho’dizite, 225. 
Rho’dochrome, 339. 
Rho’dochro’site, 210. 
Rho'donite, 268. 
Rho'dophyl'lite, 389. 
Rhomb-spar, 289, 
Rhy’'olyte, 476. 
Richellite, 203. 
Rinkite, 285. ~ 
Ripid'olite, 340. 


Ritting’erite, near Freieslebenite, - 


Riv’otite, 154. 
Rock cork, 271. 
crystal, 254, 
gas, 342. 
meal, 286. 
milk, 286. 
oil, 344. 
salt, 248. 
tallow, 347, 
Reep’perite, 277, 
Rees'slerite, 226. ; 


Rogersite, 222, . 


GENERAL INDEX. 


Romeine, Romeite, 234. 
Roscoelite, 336. 
Roselite, 184. 
Rosite, 335. 
Nosso antico, 440, 
Rosterite, 274. 
Rothofiite, 279. 
Rotlisite, 185; 382. 
tu’bellite, 305. 
Rubislite, 340. 
Ruby, Oriental, 212. 


Rubysilver, Ruby-blende, 132,133. 


Ruby, Spinel, 214. 

Ruin marble, 459. 
Ruthe’nium, Ores of, 141. 
Ru'therfordite, 223. 
Rutile, 179; 59. 


Safflorite, 182. 
Sag’enite, 179. 

Sahlite, 266. 

Sal ammoniac, 249. 
Salmiak, 249. 

Salt, Common, 248; 31. 
Samarskite, 221. 
Sandbergerite, 149. 
Sand-rock, 463. 
Sandstone, 462. 
San‘idin, 301. 
Sap’onite, 332; 329. 
Sapphire, 211. 
Sar’colite, 293. 

Sard, 256. 
Sardon’yx, 256. 
Sar’kinite, 210. 
Sartorite, 164. 
Sas’solite, Sas’solin, 109. 
Satin-spar, 229, 235. 
Saus’surite, 283; 410, 449. 
Savite, v. Natrolite. 
Scap’olite, 292; 455. 
Scar’broite, 319. 
Scheelite, 232. 
Schiller-spar, 331; .450, 
Schirmerite, 184. 
Schneebergite, 234. 
Schorl (pron. Shorl), 305. 
Schorl’omite, 314. 
Schorl-rock, 488. 
Schraufite, 349. 
Schrei’bersite, 192. 
Schréckeringite, 188. 
Schrotterite, 318. 


513 


Schwatzite, 150. 
Scleret’inite, 349. 
Scolecite, Scolezite, 321. 
Scor’cdite, 203. 
Scotiolite, 338. 
Sco’villite, 223. 
Scythe-stone, 463. 
Selenide, Lead, 164, 
Mercury, 143. 
Silver, 181, 182. 
Selenite, 229. 
Selenite, Copper, 154. 
Lead, 168. 
Selenpal’ladite, 142, 
Sel'laite, 223. 
Semseyite, 164. 
Semiopal, 260. 
Sen’armont’ite, 118. 
Serpierite, 153. 
Se’piolite, 328. 
Ser’icite, 290, 835. 
schist, 473. 
Ser’pentine, 829; 490. 
Sev’erite, 335. 
Sey'bertite, 342, 
Shale, 463. 
Siderazote, 193. 
Sid’erite, 203. 
Sideromelan, 486. 
Sid’erona’trite, 200. 
Sid’erophyl'lite, 291. 


Siegburgite, 349. 


Sie’genite, 181. 
Silaonite, 114. 
Silex = Quartz, 253. 


Silfbergite, 273. 


Sil'ica, 90, 2538, 259. 
Silicate, Copper, 157. 
Lead, 169. 
Manganese, 268, 
Nickel, 185. 
Zinc, 173, 174. 
Siliceous sinter, 261, 469. 
slate, 469. 
Silicified wood, 258. 
Silicoborocalcite, 232. 
Sillimanite, 305. 
Silt, 465. 
Silver, 129. 
compounds of, 129. 
glance, 129. 
Silver-lead ore, 135, 161. 
Sinter, Iron, 208. 


514 GENERAL INDEX. 


Sinter, Siliceous, 261. 
Simonyite, 225. 
Sipylite, 222. 
Sis’mondine, 341. 
Sisserskite, 141. 
Skolopsite, 294. 
Skutterudite, 183. 
Slags, 443. 
Slate, 463. 
Smaltite, Smaltine, 181. 
Smectite, 328. 
Smithsovite, 172. 
Snow, crystals of, 4. 
Soapstone, 826, 489. 
Soda-granite, 480, 
Soda nitre, 248. 
So’dalite, 294. 
Sodium, Compounds of, 248. 
Sommarugaite, 183. 
Som'mite, 2938. 
Sonomaite, 217.’ 
Spathic iron, 203. 
Spath'iopy’rite, 183. 
Spear pyrites, 191. 
Speckstein = Steatite, 326. 
Specular iron, 194. 
Specular schist, 473. 
Speculum nietal, 159. 
Spelter, 174. 

solder, 159, 
Spessartite, 279. 
Spheerosiderite, 204, 
Sphal’erite, 170. 
Sphene, 312. 
Spherocobaltite, 185. 
Spherulites, 445, 455, 476. 
Spilite, 485. 
Spinel’, 213. ° 
Spinthere, v. Titanite. 
Sphe’rostil’bite, 325. 
Spod ‘iosite, 234. 
Spod’umene, 269. 
Stalac’tite, 236. 
Stalag’mite, 2386. 
Stannite, 176. 


Staurolite, Staurotide, 313; 456. 


Stear’gillite, 329. 
Steatargillite, 340. 
Ste’atite, 326. 
Steatyte, 489. 
Stecleite, 326. 
Steph’anite, 133. 
Stercorite, 250. — 


Sterlingite, 290. _ 
Sternbergite, 131. 
Stetefeldite, 154. 
Stibnite, 112. 
Stilbite, 324. 
Stilpnom’elane, 329. 
Stinkstone, 287. 
Stolpenite, 329. 
Stolzite, 166. 
Strakonitzite, 317. 
Strat’ope’ite, 838. 
Strengite, 203. 
Strigovite, 3388. 
Stromey’erite, 131. 
Strontianite, 242. 
Strontium, Compounds of, 240. - 
Stru’vite, 250. 

Stii'belite, 338. 

Stiitzite, 132. 

Sty'loty’pite, 149. 

Succinite, 279, 349. 

Succinum, 349. 

Sulphatallophane, 318. 

Sulphate, Aluminium, 216. 
Ammonium, 250. 
Barium, 240. 
Calcium, 229, 280. 
Cobalt, 184. 

Copper, 152. 
Iron, 199. 

Lead, 165. 
Magnesium, 224. 
Nickel, 184. | 
Potassium, 246. 
Sodium, 246. 
Strontium, 242. 
Uranium, 188. 
Zine, 172. 

Sulphide, Antimony, 112. 

Arsenic, 111. 
Bismuth, 114. 
Cadmium, 175, 
Cobalt, 181. 
Copper, 147, 148. 
Tron, 189, 192. 
Lead, 160. 
Manganese, 206. 
Mercury, 148. 
Molybdenum, 108, 
Nickel, 181. 
Ruthenium, 141. 
Silver, 131, “9805 

olin, 17o: 


GENERAL INDEX. 515 


Sulphide, Zinc, 170. 
Sulphur, Native, 106; 38. 
Sulphuret, see Sulphide. 
Sulphuric acid, 107. 
Sulphurous acid, 107. 
Sunstone, 299, 301, 
Susan’nite, 166. 
Sus’sexite, 226. 
Sy’enyte, ATT. 
Syenyte gneiss, 477, 
Quartz, 477. 
Syl’vanite, 182, 
Sylvine, Sylvite, 248, 
Synadelphite, 210. 
Syn’genite, 246. 
Szaboite, 264. 
Szaibelyte, 225. 
Szmikite, 208. 


Tab’asheer, 261. 
Tabular spar, 265. 
Tachhy'drite, 224. 
Tach'yaphal'tite, 282. 
Tach’ylyte, 485. 
Teenite, 189. © 
Tagilite, 154. 
Tale, 326. 
Talcose schist, 489. 
Talctriplite, 209. 
Tantalite, 202. 
Tapalpite, 182. 
Ta rapa’'caite, 246. 
Tasmanite, 349, 
Taznite, 114. 
Telluride, Bismuth, 114. 
Gold, 129, 182. 
Lead, 164. 
Mercury, 148. 
Silver, 131, 182. 
Tellurite, 108. ~ 


Tellurium, Bismuthic, 102. 


Foliated, 164. 

Graphic, 132. 

Native, 108. 
Tellurous acid, 108, 
Teng’erite, 223. 
Ten’nantite, 149. 
Ten’orite, 151... 
Teph’roite, 277. 
Teph'ryte, 480, 486. 
Tere’nite, 335. 
Teschemacherite, 250. 
Teschenyte, 486, 


Tetrad’ymite, 114. 
Tetrahe'drite, 150; 121. 
Thau'masite, 239, 
Thenard’ite, 246. 
Thermonga ‘trite, 249, 
Thin’olite, 236. 
Thomsen’olite, 216. 
Thomsonite, 320. 
Thorite, 318. 
Thraulite, 338. 
Throm’'bolite, 154, 
Thulite, 285. 
Thu'mite, 286. 
Thurin’gite, 341. 
Tiemannite, 148. 
Tile Ore, 151. 
Till, 465. 
Tin, Native, 176. 
Tin ore, Tin stone, 176, 
Tin pyrites, 176. 
Tincal’conite, 247. 
Tinkal, 246. 
Titanic iron, 195. 
Titanite, 312, 
Titanium, Ores of, 178. 
Titanomor’phite, 312. 
Thinolite, 236. 
Tiza, v. Ulexite, 231. 
Tocornalite, 134. 
Tonalyte, 481. 
Topaz, 309. 

False, 255. - 

Oriental, 212. 
Topaz 'olite, 279. 
Tobermorite, 315. 
Tor’banite, 349, 352. 
Torbernite, 187. 
Touchstone, 257. 
Tour’maline, 304; 455, 
Tourmalyte, 488. 
Trach'ydol’eryte, 483. 
Trach'yte, 475; 442, 
Tract’olyte, 450. 
Trap, 481, 485. 
Trav’ersellite, 317. 
Trav’ertine, 236, 460, 
Trem ’olite, 270. 


'Tyri'ehites, 442, 


Tric’lasite, 336. 
Trid’ymite, 262; 448, 455. 


Tri ipestone, 231. 


Triph'ylite, Triphyline, 208. 


Trip’lite, 209. 


516 GENERAL INDEX. 


Triploidite, 209. 
Trip’olite, 261, 465. 
Tripolyte, 465. 
Trippkeite, 154. 
Tritochorite, 168, 
Trit’omite, 318. 
Troctolyte, 486. 
Trd‘gerite, 188, 
Troilite, 192. 

Trona, 249. 

Troostite, 178. 
Tscheffkinite, 313. 
T'schermakite, v. Oligoclase. 
Tschermigite, 217, 250. 
Tufa, Tuff, 463. 

Tufa, Calcareous, 2386. 
Tungstate, Copper, 152. 

Iron, 200. 

Lead, 166. 

Lime, 232. 
Tungstic ochre, 109. 
Tungstite, 109. 
Turgite, 199. 
Turnerite, 222. 
Turquois, 219. 
Tutenague, 186. 
Tyr'olite, 154, 
Tysonite, 221. 


Uin'tahite, 349. 
Ulexite, 231. 
Ullman’‘nite, 183. 
Ultramarine, 295. 
Unakyte, 478. 
Unghwarite, 329. 
Unionite, v. Zoisite. 
Uraconise, Uraconite, 188, 
U'ralite, 268, 451. 
Uranin, Uraninite, 186. 
U'ranite, 187. 
Uranium, Ores of, 186. 
Uranmica, 187. 
U'ranochal’cite, 188. 
U'ranocir’cite, 188. 
Uranopilite, 188. 
Uranospinite, 188. 


Uranotan’talite = Samarskite. 


U'ranothallite, 188. 
Uranothorite, 188, 318. 
Uranotil, 188. 
Uranvitriol, 188. 
Urpethite, 347. 
Urusite, 200. 


Urvdlgyite, 153, 
U'tahite, 200. 


Valentinite, 118. 

Vanadate, Copper, 154. 
Lead, 168. 

Vanad'inite, 168, 

Var'iolyte, 487. 

Varis'cite, 219. 

Vasite, 284. 

Vauque'linite, 166. 

Velvet copper ore, 153. 

Venasquite, 337, — 

Ven’erite, 841. 

Venice white, 241. 

Verd-antique, 880, 461, 490. 
Oriental 440. 

Verde di Corsica duro, 487. 

Vermic’ulite, 338. 

Vermilion, 148. 

Vesu vianite, 282, 

Veszelyte, 154, 

Viandite, 261. 

Vietinghofite, 221, 

Villar’site, 818. 

Vir'idite, 337. 

Vitreous copper, 146. 
silver = Argentite, 181. . 

Vitriol, Blue or Copper, 152. 
Green or Iron, 199. 
White or Zine, 172. 

Vitrophyre, 476. 

Viv'ianite, 202. 

Voglianite, 188. 

Voglite, 188. 

Voigtite, 336. 

Volborthite, 154, 

Volcanic glass, 476, . 

Volknerite, 213. , 

Vol'taite, 200. 

Voltzite, 172. 

Vorhau’serite, 830, 

Vul'pinite, 2381. 


Wacke, 464. 

Wad, 207. 
Wagnerite, 226, - ° 
Walchowite, 349. 
Walkerite, 315. 
Walpurgite, 188. 
Waltherite, 114. 


. Waluewite, 342, 


Warringtonite, v. Brochantite. 


GENERAL INDEX. 


Warwickite, 225. 
Washingtonite, 195. 
Water, 251; 4. 
Wattevillite, 246. 
Wa 'vellite, 220. 
Websterite, 218. 
Wehrlite, 114. 
Weiss-stein, 471. 
Wer'nerite, 292. 
Werthemanite, 218. 
Westanite, v. Fibrolite, 
W heel-ore, 149. 
Whetstone, 468. 
Whewellite, 289. 
White arsenic, 111. 
lead-ore, 168. 
Whitneyite, 149. 
Wichtiue, Wichtisite, 273. 
Willcoxite, 341. 
Wil'lemite, 173; 278. 
Williamsite, 330. 
Wilsonite, 335. 
Winkworthite, ». Howlite. 
Witherite, 241. 
Wiitichenite, 149, 150. 
Wittingite, 338. 
Wohilerite, 278. 


Wolfram, Wolframite, 200. 


Woll'astonite, 265. 
Woll'ongong’ite, 349. 
Wood-opal, 261. 


Wood'wardite, near Cyanotri- 


chite. 
Wulf'enite, 166. 
Wurtzite, 171. 


Xantho’conite, 149. 
Xanthophyliite, 342. 


Xanthosiderite, 199. 
Xen’otime, 222, 
Xyl'otine, 317. 


Ye'nite, 285, 
Youngite, 171. 
Ytter-garnet, 279. 
Yttrium ores, 221. 
Yttrocerite, 221. 
Yttrotantalite, 221, 
Yttrotitanite, 318, 


Zaffre, 185. 
Zar’atite, 185. 
Zeag’onite, 818. 
Zeolite Section, 819. 
Zephar’ovichite, 220. 
Zeunerite, 188. 
Zietrisikite, 347. 
Zinc, ores of, 170. 

blende, 170. 

bloom, 173. 

Native, 170. 
Zinc-aluminite, 172, 
Zincite, 171. 
Zink’enite, 164. 
Ziun’waldite, 290. 
Zipp’eite, 188. 
Zircon, 281; 455. 
Zir’conite, 281. 
Zircon-syenyte, 478, 
Zirlite, 213. 


| ZOb'litzite, 332. 


Zoi'site, 285; 456. 
Zonochlorite, 317. 
Zorgite, 164. 
Zunyite, 314. 
Zwieselite, v, Triplite, 


517 





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